Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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VERTICALLY INTERLEAVED DISTRIBUTED ANTENNA SYSTEM
TECHNICAL FIELD
[0001] The present disclosure relates to antenna systems and, more
particularly, to
in-building distributed antenna systems.
BACKGROUND
[0002] Buildings and other structures sometimes present challenges for
wireless
signal distribution. Features in such buildings, such as walls, ceilings,
doors and
furniture, may attenuate a wireless signal making wireless reception
unreliable within
all areas of the building. For example, cellular reception may be unavailable
within at
least a portion of a building due to the attenuation of building materials.
[0003] To provide greater wireless signal coverage, buildings are
sometimes
equipped with an in-building distributed antenna system (DAS). A distributed
antenna
system is a network of spatially separated antenna nodes which are connected
to a
common source via a transport medium. The antenna nodes serve to increase the
wireless coverage area within the building.
[0004] In-building distributed antenna systems have been designed to
work with
single input, single output (SISO) wireless technologies. However, such single
input,
single output wireless technologies are relatively slow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is an isometric view of an operating environment in which
example
embodiments of the present disclosure may be applied;
[0006] FIG. 2 is an isometric view of an operating environment
illustrating an in-
building distributed antenna system in accordance with example embodiments of
the
present disclosure;
[0007] FIG. 3 is a front view of a structure illustrating the in-
building distributed
antenna system of FIG. 2;
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[0008] FIG. 4 is a flowchart of a method for providing wireless coverage
in
accordance with example embodiments of the present disclosure;
[0009] FIG. 5 is an isometric view of an operating environment
illustrating a SISO in-
building distributed antenna system;
[0010] FIG. 6 is a front view of a structure illustrating the in-building
distributed
antenna system of FIG. 5;
[0011] FIG. 7 is a flowchart of a method for converting a SISO in-
building distributed
antenna system to a multiple input multiple output (MIMO) in-building
distributed
antenna system; and
[0012] FIG. 8 is an isometric view of an operating environment illustrating
a 3x3
MIMO in-building distributed antenna system in accordance with example
embodiments of the present disclosure.
[0013] Like reference numerals are used in the drawings to denote like
elements
and features.
DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS
[0014] In one aspect, the present disclosure describes an in-building
distributed
antenna system for providing wireless coverage within a coverage area which
includes
at least a portion of a structure. The in-building distributed antenna system
includes a
multiple-input and multiple-output (MIMO) radio. The MIMO radio includes a
first
branch connector and a second branch connector. The in-building distributed
antenna
system further includes a first branch transport medium coupled to the first
branch
connector and a second branch transport medium coupled to the second branch
connector. The in-building distributed antenna system further includes a
plurality of
antennas. The plurality of antennas includes one or more first branch antennas
coupled
to the first branch transport medium and one or more second branch antennas
coupled
to the second branch transport medium. The first branch antennas are
vertically
interleaved with the second branch antennas in the structure.
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[0015] In
another aspect, the present disclosure describes a method of providing
wireless coverage within a coverage area which includes at least a portion of
a
structure. The method includes: providing a multiple-input and multiple-output
radio
comprising a first branch connector and a second branch connector; connecting
a first
branch transport medium to the first branch connector; connecting a second
branch
transport medium to the second branch connector; and selectively connecting
one or
more antennas to the first branch transport medium to create one or more first
branch
antennas and selectively connecting one or more antennas to the second branch
transport medium to create one or more second branch antennas which are
vertically
interleaved with the first branch antennas.
[0016] In yet
another aspect, the present disclosure describes a method of
converting a single input single output in-building distributed antenna system
to a
multiple input multiple output in-building distributed antenna system. The
single input
single output in-building distributed antenna system includes a single-input
and single
output radio comprising a first branch connector connected to a first branch
transport
medium. The first branch transport medium includes a first branch backbone
transport
medium connected to the first branch connector and a plurality of floor
distribution
transport mediums connected to the first branch backbone transport medium and
to a
plurality of antennas distributed on a plurality of floors. At least some of
the plurality of
floor distribution transport mediums which are connected to the first branch
backbone
medium are located on adjacent floors. The method comprises: disconnecting the
single-input and single output radio from the first branch backbone transport
medium;
providing a multiple-input and multiple-output radio comprising at least two
branch
connectors including a first branch connector and a second branch connector;
connecting the first branch backbone transport medium to the first branch
connector;
connecting a second branch backbone transport medium to the second branch
connector; selectively disconnecting floor distribution transport mediums from
the first
branch backbone transport medium and connecting such floor distribution
transport
mediums to the second branch backbone transport medium to vertically
interleave
floor distribution transport mediums which are connected with the first branch
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backbone transport medium and floor distribution transport mediums which are
connected with the second branch backbone transport medium.
[0017] In one aspect, the present disclosure describes an in-building
distributed
antenna system for providing wireless coverage within a coverage area which
includes
at least a portion of a structure. The portion of the structure includes at
least a portion
of two adjacent floors. The in-building distributed antenna system comprises a
multiple-input and multiple-output radio comprising a first branch connector
and a
second branch connector. The in-building distributed antenna system further
comprises a first branch transport medium coupled to the first branch
connector and a
second branch transport medium coupled to the second branch connector. The in-
building distributed antenna system further comprises a plurality of antennas
comprising at least one first branch antenna which is connected to the first
branch
transport medium and at least one second branch antenna which is connected to
the
second branch transport medium. At least one of the first branch antennas is
disposed
on one floor of the structure and at least one second branch antenna is
disposed on
another floor of the structure which does not have a second branch antenna
disposed
thereon but which is within a coverage area of the first branch antenna.
[0018] Other example embodiments of the present disclosure will be
apparent to
those of ordinary skill in the art from a review of the following detailed
description in
conjunction with the drawings.
[0019] Referring to FIG. 1, an isometric view of an example operating
environment
101 in which example embodiments of the present disclosure may be applied is
illustrated. The operating environment 101 includes a structure 100, such as a
building.
The structure 100 is a multi-floor structure which, in the example embodiment
illustrated in FIG. 1, is a high-rise building. The structure 100 may, for
example, be a
residential structure such as an apartment building, a commercial structure
such as an
office building, an industrial structure such as a factory building, an event
center such as
a stadium, arena, concert hall, opera house, etc., a retail structure such as
a shopping
mall, or a mixed use structure. Other types of structures are also possible.
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[0020] In the example illustrated, the structure 100 is generally shaped
as a
rectangular prism. However, the embodiments described in the present
disclosure may
be applied to structures 100 which take other forms.
[0021] In at least some example embodiments, the structure 100 includes
a
plurality of floors 102a, 102b, 102c, 102d, 102e, 102f. To illustrate the
multi-floor
nature of the structure 100 of FIG. 1, each floor 102a, 102b, 102c, 102d,
102e, 102f has
been illustrated to include a set of windows. Also, to illustrate the multi-
floor nature of
the structure 100 of FIG. 1, a demarcating line has been drawn on the exterior
surface
of the structure 100 of FIG. 1 at the location where structural features (such
as a floor
and ceiling) may separate the floors 102a, 102b, 102c, 102d, 102e, 102f.
[0022] In the illustrated example, the structure 100 includes six
floors: a first floor
102a (which may also be referred to as a bottom floor 102a) located at the
bottom of
the structure, a second floor 102b located adjacent to the first floor 102a
and
immediately above the first floor 102a, a third floor 102c located adjacent to
the
second floor 102b and immediately above the second floor 102b, a fourth floor
102d
located adjacent to the third floor 102c and immediately above the third floor
102c, a
fifth floor 102e located adjacent to the fourth floor 102d and immediately
above the
fourth floor 102d, and a sixth floor 102f (which may also be referred to as a
top floor
102f) located adjacent to the fifth floor 102e and immediately above the fifth
floor
102e. The structure 100 may, however, include a greater or a fewer number of
floors
than the structure 100 illustrated in FIG. 1.
[0023] The example embodiments described herein may be used to
distribute a
wireless signal to at least a portion of the interior of the structure 100.
The wireless
signal may be provided by a wireless communications system 110 which is
configured to
provide wireless communication services to wireless communication devices 201
which
operate within a coverage area associated with the wireless communications
system
110. In at least some example embodiments, the wireless communications system
110
is configured to communicate with the wireless communication devices 201 using
a
multiple-input, multiple output (MIMO) communication protocol such as Wi-FiTM
(such
as the Institute of Electrical and Electronic Engineers (IEEE) 802.11n
standard), the 4G
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standard, the Long Term Evolution (LTE) standard such as the 3GPP Long Term
Evolution (LTE) standard, the Worldwide Interoperability for Microwave Access
(WiMAX) standard or the Evolved High-Speed Packet Access (HSPA+) standard.
Other
MIMO based communications protocols, including variations and evolutions of
the
standards described above may also be used.
[0024] MIMO involves the use of multiple antennas at both a transmitter
and a
receiver to improve communication performance. MIMO may be used in the
wireless
communications system 110 to provide increases in data throughput and link
range.
This may be achieved through spectral efficiency and link reliability or
diversity.
[0025] In at least some example embodiments, the wireless communications
system 110 may also be configured to also provide communications according to
non-
MIMO based communication protocols in addition to MIMO based communications.
For example, the wireless communications system 110 may provide communications
according to analog, digital or dual-mode communications system standards such
as,
for example, the Frequency Division Multiple Access (FDMA) standard, the Code
Division Multiple Access (CDMA) standard, the Wideband CDMA (WCDMA) standard,
the Global System for Mobile Communications (GSM) standard, the Enhanced Data
GSM Environment (EDGE) standard, the Universal Mobile Telecommunications
System
(UMTS) standard. Other communications protocols, including variations and
evolutions
of the standards described above may also be used.
[0026] The wireless communication devices 201 which are configured to
communicate with the wireless communications system 110 may include any
electronic
devices that are configured for wireless communications using a communication
protocol provided by the wireless communications system 110. In various
example
embodiments, the wireless communication devices 201 may include, for example,
a
cellular phone, a snnartphone, a personal computer, a tablet computer, a
gaming
device, an audio or video player (such as a television or MP3 player), a
navigational
device (such as a global positioning system (GPS) device), a wireless
peripheral (such as
a printer), or a pager. Other types of wireless communication devices 201
apart from
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those specifically listed above may also be used in the wireless
communications system
110.
[0027] In at
least some example embodiments, such as the example embodiment
illustrated in FIG. 1, the wireless communications system 110 may be a
cellular
communications network. The cellular communications network includes at least
one
communications site 111 which transmits and receives a cellular wireless
signal 108.
The communications site 111 may be a fixed-location communications site 111
such as
a cell site or base station. The communications site 111 provides radio
coverage over an
associated geographic area, which may be referred to as a cell. The
communications
site 111 may provide wireless communication services for wireless
communication
devices 201 located within the coverage area of the communications site 111.
The
communications site 111 includes a transceiver 106 which is electrically
connected to
an antenna 109. The antenna 109 may be mounted on an antenna support structure
107, such as a tower or a building.
[0028] The
wireless communications system 110 will also include other
communications sub-systems 112 which have, for the purpose of illustration,
been
displayed in block form. It will be appreciated that these communications sub-
systems
112 will generally take other forms and that various components of the
communications sub-systems 112 may be physically or logically separated from
one
another. By way of example, the communications sub-systems 112 may include
communication equipment such as servers, routers and systems which are
configured
to provide wireless services to the wireless communication devices 201. Such
wireless
services may include voice communication services which permit the wireless
communication device 201 to audibly communicate with other devices. The
wireless
services may also permit wireless communication devices 201 to transmit other
data to
other devices. In at least some example embodiments, the communications sub-
system
112 is connected to a network 113, which may include the Internet. The
communications sub-systems 112 may provide network connectivity to wireless
communication devices 201 to allow such devices to access network connected
systems
and devices, such as content servers.
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[0029] The structure 100 may include various features which act to
attenuate a
wireless signal (such as the cellular wireless signal 108). For example,
walls, ceilings,
doors and furniture may attenuate a wireless signal. Due to such attenuation,
the
structure 100 may have one or more zones where reception of cellular wireless
signals
108 from external communication sites 111 may be poor.
[0030] Referring now to FIGs. 2 and 3, in order to provide wireless
coverage within
the structure 100, the wireless communications system 110 includes an in-
building
distributed antenna system 202. The in-building distributed antenna system 202
may,
in some example embodiments, be configured to provide wireless coverage to all
internal areas of the structure 100. In other example embodiments, the in-
building
distributed antenna system 202 may provide wireless coverage within only a
portion of
the structure 100, such as, for example, a dead zone within the structure 100
where
external communication sites 111 do not provide reliable wireless coverage.
Such a
dead zone may exist, for example, near the center of the structure 100, away
from the
structure's extremities.
[0031] In order to better illustrate the in-building distributed antenna
system 202,
in FIG. 2, the external walls of the structure 100 have been removed from the
illustration. That is, FIG. 2 illustrates an isometric view of the operating
environment
101 in which the external walls of the structure 100 have been removed to
better
illustrate the in-building distributed antenna system 202. FIG. 3 illustrates
a front view
of the structure 100 of FIG. 2 to further illustrate the in-building
distributed antenna
system 202.
[0032] The in-
building distributed antenna system 202 provides MIMO wireless
coverage within a coverage area which includes at least a portion of a
structure 100.
More particularly, the in-building distributed antenna system 202 provides
MIMO
wireless coverage within a portion of at least two adjacent floors of the
structure 100.
In the example embodiment illustrated, the in-building distributed antenna
system 202
provides MIMO wireless coverage over all six floors 102a, 102b, 102c, 102d,
102e, 102f
of the structure 100. An example wireless communication device 201 has been
illustrated on the sixth floor 102f (i.e. the top floor) to illustrate the
operation of the in-
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building distributed antenna system 202 to provide MIMO wireless
communications to
a wireless communication device 201.
[0033] The in-building distributed antenna system 202 includes a
multiple-input and
multiple-output (MIMO) radio 210. In the example embodiment illustrated in
FIG. 2,
the wireless communications system 110 is a cellular communications network
and the
MIMO radio 210 is connected to the communications sub-systems 112. The MIMO
radio 210 may be connected to the communications sub-system 112 via a wired
transport medium 223 such as, for example, fibre optic cabling. The MIMO radio
210
may, in other example embodiments, be connected to the communications sub-
system
112 via wireless communications. For example, the MIMO radio 210 may be
connected
to the communication sub-systems 112 through wireless communications via a
communications site 111 which has a coverage area that includes the area in
which the
MIMO radio 210 is located.
[0034] In the example illustrated, the MIMO radio 210 is illustrated as
being located
at the exterior of the base of the structure 100 (i.e. near the first floor
102a). However,
in other embodiments, the MIMO radio may be located internal to the structure
100
and/or may be located away from the base of the structure 100.
[0035] The MIMO radio 210 includes a first branch connector and a second
branch
connector. The first branch connector is associated with a first communication
branch
(which may be referred to as branch A) of the MIMO radio 210 and the second
branch
connector is associated with a second communication branch (which may be
referred to
as branch B) of the MIMO radio 210.
[0036] In order to benefit from MIMO capabilities of the MIMO radio 210,
a
wireless communication device 201 must be within a coverage area of a first
branch
wireless signal 220 associated with the first branch (i.e. branch A) of the
MIMO radio
210 and must also be within a coverage area of a second branch wireless signal
222
associated with a second branch (i.e. branch B) of the MIMO radio 210. As will
be
described in greater detail below, the in-building distributed antenna system
202 may
be arranged so that, where a wireless signal associated with a branch does not
originate
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on a given floor, that wireless signal associated with that branch will
originate from an
adjacent floor. Thus, when a wireless communication device 201 is within the
coverage
area of the in-building distributed antenna system 202, the wireless
communication
device 201 may receive a wireless signal associated with one branch from an
antenna
mounted on the floor on which the wireless communication device 201 is located
and
may receive a wireless signal associated with another branch from an antenna
mounted
on a floor which is adjacent to the floor on which the wireless communication
device
201 is located.
[0037] In order to distribute signals sent and received from the MIMO
radio 210 to
other areas of the structure 100, the branch connectors are electrical
connectors which
are configured to connect to one or more wired transport mediums. More
particularly,
a first branch transport medium 204 is coupled to the first branch connector
of the
MIMO radio 210 and a second branch transport medium 206 is coupled to the
second
branch connector of the MIMO radio 210.
[0038] The first branch transport medium 204 includes a first branch
backbone
transport medium 208 which vertically distributes first branch signals sent
and received
from the first branch (i.e. branch A) of the MIMO radio 210 in the structure
100.
Similarly, the second branch transport medium 206 includes a second branch
backbone
transport medium 209 which vertically distributes second branch signals sent
and
received from the second branch (i.e. branch B) of the MIMO radio 210 in the
structure
100. In at least some example embodiments, the first branch backbone transport
medium 208 may be referred to as first branch vertical cabling and the second
branch
backbone transport medium 209 may be referred to as second branch vertical
cabling.
While the first branch backbone transport medium 208 and the second branch
backbone transport medium 209 are generally used to distribute the first
branch signals
and second branch signals vertically (i.e. to distribute these signals to
other floors),
these backbone transport mediums 208, 209 may have a horizontal component to
their
direction. For example, the backbone transport mediums 208, 209 may include
one or
more jogs which may result from the design of the structure 100. Accordingly,
the
backbone transport mediums 208, 209 may, to some extent, distribute the first
branch
signals and the second branch signals horizontally.
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[0039] In at
least some example embodiments, the backbone transport mediums
208, 209 are comprised of coaxial cabling. In other example embodiments, other
types
of cabling (such as fibre optic cabling) may be used. The backbone transport
medium
208, 209 may be routed through an electrical conduit in the structure 100.
[0040] The first branch transport medium 204 further includes one or more
first
branch floor distribution transport mediums 240 and the second branch
transport
medium 206 further includes one or more second branch floor distribution
transport
mediums 242. To enhance the clarity of FIG. 2, only one first branch floor
distribution
transport medium 240 has been labelled (i.e. the first branch floor
distribution
transport medium 240 on the sixth floor 120f) and one second branch floor
distribution
transport medium 242 has been labelled (i.e. the second branch floor
distribution
transport medium 242 on the fifth floor 102e). In FIG. 3, a plurality of first
branch floor
distribution transport mediums 240 and second branch floor distribution
transport
mediums 242 have been labelled.
[0041] The first branch floor distribution transport mediums 240 are
connected to
the first branch backbone transport medium 208 using a suitable connector.
Similarly,
the second branch floor distribution transport mediums 242 are connected to
the
second branch backbone transport medium 209 using a suitable connector. The
first
branch floor distribution transport mediums 240 distribute the first branch
signal, which
is associated with the first branch of the MIMO radio 210, to other areas of a
floor (i.e.
areas on a floor which may be away from the first branch backbone transport
medium
208). Similarly, the second branch floor distribution transport mediums 242
distribute
the second branch signal, which is associated with the second branch of the
MIMO
radio 210, to other areas of a floor (i.e. areas which may be away from the
second
branch backbone transport medium 209). The floor distribution transport
mediums
240, 242 are generally used to distribute signals to other areas of a floor
(and not to
other floors). In contrast, the backbone transport mediums 208, 209 are
generally used
to distribute signals to other floors.
[0042] In at least some example embodiments, the first branch floor
distribution
transport mediums 240 may be referred to as first branch horizontal cabling
and the
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second branch floor distribution transport mediums 242 may be referred to as
second
branch horizontal cabling. While the first branch floor distribution transport
mediums
240 and the second branch floor distribution transport mediums 242 are
generally used
to distribute the first branch signals and second branch signals horizontally
(i.e. to
distribute these signals to other areas of a floor), these floor distribution
transport
mediums 240, 242 may have a vertical component to their direction. For
example, the
floor distribution transport mediums 240, 242 may include one or more jogs
which may
result from the design of the structure 100. Accordingly, the floor
distribution transport
mediums 240, 242 may, to some extent, distribute the first branch signals and
the
second branch signals vertically.
[0043] In at
least some example embodiments, the floor distribution transport
mediums 240, 242 are comprised of coaxial cabling. In other example
embodiments,
other types of cabling (such as fibre optic cabling) may be used. The floor
distribution
transport mediums 240, 242 may be routed through an electrical conduit in the
structure 100.
[0044] In at
least some example embodiments, each floor distribution transport
medium 240, 242 is associated with a separate one of the floors 102a, 102b,
102c,
102d, 102e, 102f of the structure 100. That is, each floor distribution
transport
mediums 240, 242 routes one of the branch signals to a separate one of the
floors 102a,
102b, 102c, 102d, 102e, 102f.
[0045] The in-
building distributed antenna system 202 further includes a plurality of
antennas 230, 232. The antennas 230, 232 may, in at least some example
embodiments, be ceiling mounted antennas which may be mounted on the ceiling
associated with each floor 102a, 102b, 102c, 102d, 102e, 102f. In at least
some
example embodiments, the antennas 230, 232 may be omni-directional in-building
antennas. By way
of example and not limitation, in at least some example
embodiments, the antennas 230, 232 may be CELLMAX-0-CPUSEiT" antennas which
are
manufactured by Cell-maxTM which is a trademark of ConnnnScope. The antennas
230,
232 may include electrical connectors for connecting the antennas to the
transport
mediums 204, 206. More particularly, the antennas 230, 232 may include
electrical
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connectors for connecting the antennas to the floor distribution transport
mediums
240, 242. The electrical connectors may, for example, be type N connectors
which are
threaded radio frequency (RF) connectors used to join coaxial cables.
[0046] The antennas 230, 232 include one or more first branch antenna
230 and
one or more second branch antenna 232. The first branch antennas 230 are
coupled to
the first branch transport medium 204 and the second branch antennas 232 are
coupled to the second branch transport medium 206. More particularly, the
first
branch antennas 230 are coupled to the first branch floor distribution
transport
mediums 240 and the second branch antennas 232 are coupled to the second
branch
floor distribution transport mediums 242.
[0047] In at least some example embodiments, the first branch antennas
230 and
the second branch antennas 232 may be the same type of antenna. That is, in
some
example embodiments, the only difference between first branch antennas 230 and
second branch antennas 232 is that first branch antennas are connected to the
first
branch transport medium 204 while second branch antennas are connected to the
second branch transport medium 206. In at least some example embodiments, both
the first branch antennas and the second branch antennas are commonly
polarized
antennas, such as vertically polarized antennas. In other example embodiments,
the
first branch antennas 230 may differ from the second branch antennas 232 in
other
aspects. For example, in at least some example embodiments, the first branch
antennas 230 may be differently polarized than the second branch antennas 232.
For
example, the first branch antennas may be horizontally polarized antennas and
the
second branch antennas may be vertically polarized antennas. The use of
differently
polarized antennas may assist to differentiate first branch signals and second
branch
signals.
[0048] In order to reduce the amount of cabling required to form the
first branch
transport medium 204 and the second branch transport medium 206, the first
branch
antennas 230 are vertically interleaved with the second branch antennas 232 in
the
structure 100. As illustrated in FIGs. 2 and 3, the first branch antennas 230
are
vertically interleaved with the second branch antennas 232 on a floor-wise
basis. That
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is, the first branch antennas 230 and the second branch antennas 232 are
distributed
on alternating floors 102a, 102b, 102c, 102d, 102e, 102f of the structure 100.
In at least
some example embodiments, the antennas 230, 232 are distributed so that odd
numbered floors contain only antennas associated with one branch and even
numbered
floors contain only antennas associated with the other branch. For example, in
some
embodiments, only first branch antennas 230 may be distributed on odd numbered
floors and only second branch antennas 232 may be distributed on even numbered
floors. That is, odd numbered floors may not contain any second branch
antennas 232
and even numbered floors may not contain any first branch antennas. Similarly,
in
other embodiments, only first branch antennas 230 may be distributed on even
numbered floors and only second branch antennas 232 may be distributed on odd
numbered floors. In such embodiments, odd numbered floors may not contain any
first
branch antennas 230 and even numbered floors may not contain any second branch
antennas 232.
[0049] Accordingly, in at least some example embodiments, the in-building
distributed antenna system 202 may include a plurality of antennas 230, 232
comprising
at least one first branch antenna 230 which is connected to the first branch
transport
medium 204 and at least one second branch antenna 232 which is connected to
the
second branch transport medium 206. At least one of the first branch antennas
230 is
disposed on a floor of the structure 100 which does not have a second branch
antenna
232 disposed thereon and at least one of the second branch antennas 232 is
disposed
on a floor of the structure 100 which does not have a first branch antenna 232
disposed
thereon but which is within a coverage area of one of the first branch
antennas 230.
[0050] The floors on which first branch antennas 230 are distributed may
be
referred to as first branch floors. In the example embodiment of FIGs. 2 and
3, the first
branch floors are the even-numbered floors (i.e. the second floor 102b acts as
a first
first branch floor, the fourth floor acts as a second first branch floor 102d
and sixth floor
102f acts as a third first branch floor). The floors on which second branch
antennas 232
are distributed may be referred to as second branch floors. In the example
embodiment of FIGs. 2 and 3, the second branch floors are the odd-numbered
floors
(i.e. the first floor 102a acts as a first second branch floor, the third
floor 102c acts as a
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second second branch floor and fifth floor 102e acts as a third second branch
floor). In
the illustrated example embodiment, no second branch antennas 232 are
distributed
on a first branch floor and no first branch antennas 230 are distributed on a
second
branch floor.
[0051] In the example embodiment of FIGs. 2 and 3, on each floor all of the
antennas on that floor provide a signal associated with only one branch. All
antennas
on a given floor provides only either a first branch wireless signal 220 or a
second
branch wireless signal 222 and is adjacent to a floor that provides the signal
associated
with the other branch. That is, a first branch floor, which provides a first
branch
wireless signal 220, is adjacent to at least one second branch floor 222 which
provides
the second branch wireless signal 222. Each floor includes either all first
branch
antennas or all second branch antennas. The first branch antennas 230 and the
second
branch antennas have a coverage area which includes at least a portion of the
floor on
which they are distributed and which also includes at least a portion of a
floor which is
adjacent to the floor on which they are distributed.
[0052] As illustrated in FIGs. 2 and 3, this arrangement permits a
wireless
communication device 201 located on one of the floors within the coverage area
of the
in-building distributed antenna system 202 to receive both a first branch
wireless signal
220 and a second branch wireless signal 222. The signal associated with one of
the
branches is received from the floor where the wireless communication device
201 is
located and the signal associated with the other one of the branches is
received from
an adjacent floor. The adjacent floor from which the signal associated with
the other
one of the branches is received may, depending on the design of the in-
building
distributed antenna system 202 and the location of the wireless communication
device
201, be the floor above the floor where the wireless communication device 201
is
located, the floor below the floor where the wireless communication device 201
is
located, or both the floors above and below the floor where the wireless
communication device 201 is located.
[0053] As illustrated in FIGs. 2 and 3, the first branch floor
distribution transport
mediums 240 and the second branch floor distribution transport mediums 242 are
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vertically interleaved in the structure 100. Accordingly, at least one floor
contains a first
branch floor distribution transport medium 240 but does not include a second
branch
floor distribution transport medium 242. The floor which includes a first
branch floor
distribution transport medium 240 but does not include a second branch floor
distribution transport medium 242 is adjacent to at least one floor which
includes a
second branch floor distribution transport medium 242 but which does not
include a
first branch floor distribution transport medium 240.
[0054] More particularly, first branch floors (i.e. floors which contain
first branch
antennas 230 but not second branch antennas 232) may include only first branch
floor
distribution transport mediums 240 and may not include second branch floor
distribution transport mediums 242. Similarly, second branch floors (i.e.
floors which
contain second branch antennas 232 but not first branch antennas 230) may
include
only second branch floor distribution transport mediums 242 and may not
include first
branch floor distribution transport mediums 240. That is, the first branch
floor
distribution transport mediums 240 and the second branch floor distribution
transport
mediums may be located on alternating floors of the structure 100.
[0055] By not including a floor distribution transport medium associated
with every
branch on every floor of the structure 100, the in-building distributed
antenna system
202 may reduce the amount of cabling which is required to provide MIMO
communications within the structure 100.
[0056] The in-building distributed antenna system 202 may include
additional
features apart from those specifically discussed above. For example, in at
least some
embodiment, the in-building distributed antenna system 202 may include one or
more
amplifiers, splitters, and/or connectors.
[0057] Furthermore, while the example wireless communications systems 110
are
generally illustrated as cellular systems, the distributed antenna systems and
the
methods described herein may be used with other types of MIMO wireless
communications systems 110 to provide wireless coverage within structures. For
example, in at least some example embodiments, the in-building distributed
antenna
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system 202 described herein may be used to provide wireless local area network
(WLAN) coverage.
[0058] Referring now to FIG. 4, a flowchart of an example method 400 is
illustrated.
The method 400 of FIG. 4 illustrates an example embodiment of a method for
providing
wireless coverage within a coverage area which includes at least a portion of
a structure
100 (FIGs. 1 to 3). The portion of the structure 100 includes at least a
portion of two
adjacent floors. Any of the components or features of the method 400 of FIG. 4
may be
the same or analogous components to the components or features discussed above
with reference to FIGs. 2 and 3.
[0059] First, at 402, a MIMO radio 210 (FIGs. 2 and 3) is provided. The
MIMO radio
210 includes a first branch connector and a second branch connector. The MIMO
radio
210 may be connected to a communications sub-system 112 via wired or wireless
transport mediums. The MIMO radio 210 includes a first branch connector and a
second branch connector. The first branch connector is associated with a first
communication branch (which may be referred to as branch A) of the MIMO radio
210
and the second branch connector is associated with a second communication
branch
(which may be referred to as branch B) of the MIMO radio 210.
[0060] Next, at 404, a first branch transport medium 204 may be
connected to the
first branch connector of the MIMO radio 210. At 406, a second branch
transport
medium 206 may be connected to the second branch connector of the MIMO radio
210.
[0061] At 408, one or more antennas are selectively connected to the
first branch
transport medium 204 to create one or more first branch antennas 230 and one
or
more antennas are selectively connected to the second branch transport medium
206
to create one or more second branch antennas 232. The antennas are selectively
connected so that the first branch antennas 230 are vertically interleaved
with the
second branch antennas 232.
[0062] In at least some example embodiments, the antennas are
selectively
connected to the transport mediums to vertically interleave the antennas 230
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connected to the first branch transport medium 204 with the antennas 232
connected
to the second branch transport medium 206 on a floor-wise basis. That is, the
antennas
230, 232 distributed on alternating floors may be alternatingly connected to
either the
first branch transport medium 204 on the second branch transport medium 206 so
that
the first branch antennas 230 and the second branch antennas 232 are
distributed on
alternating floors 102a, 102b, 102c, 102d, 102e, 102f of the structure 100.
[0063] In at least some example embodiments, the antennas 230, 232 on
odd
numbered floors are only connected to the transport medium 204, 206 associated
with
one branch of the MIMO radio 210 and the antennas 230, 232 on even numbered
floors
are only connected to the transport medium 204, 206 associated with another
branch
of the MIMO radio 210.
[0064] As discussed above, the floors on which first branch antennas 230
are
distributed may be referred to as first branch floors. That is, the floors on
which
antennas are connected to the first branch transport medium 204 may be
referred to as
first branch floors. Similarly, the floors on which second branch antennas 232
are
distributed and on which antennas are connected to the second branch transport
medium 206 may be referred to as second branch floors. Accordingly, in at
least some
embodiments, the antennas distributed on a first branch floor are connected to
the first
branch transport medium 204 and the antennas distributed on a second branch
floor,
which is adjacent to the first branch floor, are connected to the second
branch
transport medium 206. In at least some such embodiments, no antennas on the
first
branch floor are connected to the second branch transport medium 206 and no
antennas on the second branch floor are connected to the first branch
transport
medium.
[0065] In at least some example embodiments, the methods and systems
described
herein may be used to convert a single input single output (SISO) in-building
distributed
antenna system 502 into a multiple input multiple output (MIMO) in-building
distributed antenna system 202, such as the multiple input multiple output
(MIMO) in-
building distributed antenna system 202 of FIGs. 2 to 3.
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[0066] An example of single input single output (SISO) in-building
distributed
antenna system 502 is illustrated in FIGs. 5 and 6. The SISO in-building
distributed
antennas system 502 may be used to distribute a SISO wireless signal to a
structure 100
such as the structure described above with reference to FIG. 1. The SISO
wireless signal
may be generated by a wireless communications system 110 such as the wireless
communications system 110 discussed above with reference to FIG. 1.
[0067] The SISO in-building distributed antennas system 502 includes a
SISO radio
510 which may be connected to a communications sub-system 112 associated with
the
wireless communications system 110. Unlike the MIMO radio 210 of FIGs. 2 and
3, the
SISO radio 510 of FIG. 5 only has a first branch connector. That is, the SISO
radio 510
does not include a second branch connector associated with a second branch of
the
SISO radio 510 (since the SISO radio 510 has only a single branch).
[0068] The first branch connector of the SISO radio 510 is connected to
a first
branch transport medium 204. The first branch transport medium 204 may include
a
first branch backbone transport medium 208 which is connected to the first
branch
connector. The first branch backbone transport medium 208 vertically
distributes first
branch signals sent and received from the first branch of the SISO radio 510
in the
structure 100. The first branch backbone transport medium 208 may be similar
to or
the same as the first branch backbone transport medium 208 discussed in FIGs.
2 and 3
above with reference to the MIMO in-building distributed antenna system 202.
[0069] However, unlike some embodiments of the MIMO in-building
distributed
antenna system 202 of FIGs. 2 and 3, the SISO in-building distributed antenna
system
202 includes first branch antennas 230 and first branch floor distribution
transport
mediums 240 on all floors, including adjacent floors. That is, in the SISO in-
building
distributed antenna system 202, a first branch floor distribution transport
medium 240
is located on a floor which is adjacent to a floor containing another first
branch floor
distribution transport medium 240 and a first branch antenna 230 is
distributed on a
floor which is adjacent to a floor containing another first branch antenna
230.
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[0070] More particularly, in the SISO in-building distributed antenna
system 502, a
plurality of first branch floor distribution transport mediums 240 connect to
the first
branch backbone transport medium 208 and to first branch antennas 230. At
least
some of the first branch floor distribution transport mediums 240 are located
on floors
which are adjacent to floors where first branch floor distribution transport
mediums
240 are also located. Similarly, at least some of the first branch antennas
230 (i.e. the
antennas which are indirectly connected to the first branch of the SISO radio
510) are
located on floors which are adjacent to a floor having another one of the
first branch
antennas 230. That is, at least some of the plurality of floor distribution
transport
mediums which are connected to the first branch backbone medium are located on
adjacent floors.
[0071] In the example embodiment illustrated in FIGs. 5 and 6, the SISO
in-building
distributed antenna system 502 includes a floor distribution transport medium
240 on
each floor. Each of the floor distribution transport mediums 240 connects to
the first
branch backbone transport medium 208 and to first branch antennas 230.
[0072] An overview of a SISO in-building distributed antenna system 502
having
been provided, reference will now be made to FIG. 7 which illustrates an
example
embodiment of a method 700 of converting a single input single output in-
building
distributed antenna system 502 (such as the SISO in-building distributed
antenna
system 502 of FIGs. 5 and 6) to a multiple input multiple output in-building
distributed
antenna system (such as the MIMO in-building distributed antenna system 202 of
FIGs.
2 and 3). Any of the components or features of the method 700 of FIG. 7 may be
the
same or analogous components to the components or features discussed above
with
reference to FIGs. 2 and 3 and/or the components or features discussed above
with
reference to FIGs. 5 and 6.
[0073] In at least some example embodiments, at 702 the SISO radio 510
may be
disconnected from the first branch backbone transport medium 208.
[0074] At 704, a MIMO radio 210 may be provided in the structure 100.
The MIMO
radio may be of the type described above with reference to FIGs. 2 and 3. The
MIMO
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radio 210 may include at least two branch connectors, including a first branch
connector and a second branch connector.
[0075] At 706, the first branch backbone transport medium 208, which was
formerly connected to the SISO radio 510, may be connected to the first branch
connector of the MIMO radio.
[0076] Similarly, at 708, a second branch backbone transport medium 209
may be
connected to the second branch connector of the MIMO radio 210. Since the SISO
in-
building distributed antenna system 502 does not rely on multiple branches,
708 may
include running a second branch backbone transport medium 209 through the
structure
100. Since the backbone transport mediums 208, 209 are used to vertically
distribute
branch signals, the second branch backbone transport medium 209 may be routed
along a substantially vertical path. In at least some embodiments, the second
branch
backbone transport medium may be routed through an electrical conduit located
in the
structure 100.
[0077] At 710, floor distribution transport mediums 240 (such as those
illustrated in
FIGs. 5 and 6) are selectively disconnected from the first branch backbone
transport
medium 208 and connected to the second branch backbone transport medium 209.
The floor distribution transport mediums 240 are selectively connected in a
manner
which vertically interleaves floor distribution transport mediums which are
connected
with the first branch backbone and floor distribution transport mediums which
are
connected with the second branch backbone. In at least some example
embodiments,
this may be done by disconnecting the floor distribution transport medium on
every
other floor from the first branch backbone transport medium 208 and connecting
that
disconnected floor distribution transport medium to the second branch backbone
transport medium 209.
[0078] The MIMO in-building distributed antenna system described above
has
generally been described in relation to a two-by-two (2x2) MIMO
implementation. A
two-by-two (2x2) MIMO implementation is a system which uses two antennas at
both a
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transmitter and a receiver. That is, the MIMO in-building distributed antenna
system
has two branches
[0079] The
systems and methods described herein may, however, be extended to
MIMO systems with more than two branches. For example, in at least some
example
embodiments, the MIMO system may be a three-by-three (3x3) MIMO configuration.
That is, the MIMO in-building distributed antenna system may have three
branches,
which may be referred to as branch A, branch B, and branch C.
[0080]
Referring now to FIG. 8, an example embodiment of a 3x3 MIMO in-building
distributed antenna system 802 is illustrated. FIG. 8 illustrates a structure
100 in which,
for the purpose of illustration, external walls have been removed. The 3x3
MIMO in-
building distributed antenna system 802 may, in some example embodiments, be
configured to provide wireless coverage to all internal areas of the structure
100. In
other example embodiments, the in-building distributed antenna system 202 may
provide wireless coverage within only a portion of the structure 100, such as,
for
example, a dead zone within the structure 100 where external communication
sites 111
do not provide reliable wireless coverage.
[0081] The in-
building distributed antenna system 802 includes a 3x3 MIMO radio
810. The 3x3 MIMO radio 810 may be connected to a communications sub-system
112,
such as the communications sub-system 112 discussed above with reference to
FIG. 1.
[0082] The 3x3 MIMO radio 810 includes three branch connectors: a first
branch
connector, a second branch connector, and a third branch connector. The first
branch
connector is associated with a first communication branch (which may be
referred to as
branch A) of the 3x3 MIMO radio 810, the second branch connector is associated
with a
second communication branch (which may be referred to as branch B) of the 3x3
MIMO
radio 810, and the third branch connector is associated with a third
communication
branch (which may be referred to as branch C).
[0083] In
order to benefit from the 3x3 MIMO capabilities of the 3x3 MIMO radio
810, a wireless communication device 201 must be within a coverage area of a
first
branch wireless signal 220 associated with the first branch (i.e. branch A) of
the 3x3
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MI MO radio 810 and also within a coverage area of a second branch wireless
signal 222
associated with the second branch (i.e. branch B) of the 3x3 MIMO radio 810
and must
also be within a coverage area of a third branch wireless signal 823
associated with the
third branch (i.e. branch C) of the 3x3 MIMO radio 810.
[0084] As in the embodiment of FIGs. 2 to 3, the in-building distributed
antenna
system 802 of FIG. 8 includes a first branch transport medium 204 which is
coupled to
the first branch connector of the MIMO radio 810 and also includes a second
branch
transport medium 206 which is coupled to the second branch connector of the
MIMO
radio 810. The in-building distributed antenna system 802 of FIG. 8 also
includes a third
branch transport medium 806 which is coupled to the third branch connector of
the
MIMO radio 810.
[0085] In a manner which is similar to the 2x2 MIMO system of FIGs. 2
and 3, the
first branch transport medium 204 includes a first branch backbone transport
medium
208 which vertically distributes first branch signals sent and received from
the first
branch (i.e. branch A) of the 3x3 MIMO radio 810 in the structure 100.
Similarly, the
second branch transport medium also includes a second branch backbone
transport
medium 209 which vertically distributes second branch signals sent and
received from
the second branch (i.e. branch B) of the 3x3 MIMO radio 810 in the structure
100. The
third branch transport medium 806 includes a third branch backbone transport
medium
808 which vertically distributes third branch signals sent and received from
the third
branch (i.e. branch C) of the 3x3 MIMO radio 810 in the structure 100. The
first branch
backbone transport medium 208, the second branch backbone transport medium 209
and the third branch backbone transport medium 808 may be of the type
discussed
above with reference to the backbone transport mediums 208, 209 of FIGs. 2 and
3.
[0086] The first branch transport medium 204 includes one or more first
branch
floor distribution transport mediums 240 and the second branch transport
medium 206
further includes one or more second branch floor distribution transport
mediums 242.
Similarly, the third branch transport medium 806 includes one or more third
branch
floor distribution transport mediums 843. The floor distribution transport
mediums
240, 242, 843 are connected to respective backbone transport mediums 208, 209,
808
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(i.e. the first branch floor distribution transport mediums 240 are connected
to the first
branch backbone transport medium 208, the second branch floor distribution
transport
mediums 242 are connected to the second branch backbone transport medium 209
and
the third branch floor distribution transport mediums 843 are connected to the
third
branch backbone transport medium 808).
[0087] The floor distribution transport mediums 240, 242, 843 distribute
branch
signals to other areas of a floor (i.e. areas which are away from the area
where the floor
distribution transport mediums 240, 242, 843 connect to the backbone transport
mediums 208, 209, 808).
[0088] The floor distribution transport mediums 240, 242, 843 may be wired
connectors such as, for example, coaxial cabling.
[0089] The in-building distributed antenna system 802 further includes a
plurality of
antennas 230, 232, 833. The antennas 230, 232, 833 may be of the type
discussed
above with reference to FIGs. 2 and 3. However, in the embodiment of FIG. 8,
at least
some of the antennas 833 are connected to the third branch transport medium
806.
Such antennas may be referred as third branch antennas.
[0090] The first branch antennas 230 (i.e. the antennas connected to the
first
branch transport medium 204) are vertically interleaved with the second branch
antennas 232 (i.e. the antennas connected to the second branch transport
medium
233) and are also vertically interleaved with the third branch antennas 833
(i.e. the
antennas connected to the third branch transport medium 806).
[0091] More particularly, on at least some of the floors 102a, 102b,
102c, 102d,
102e, 102f of the structure 100, antennas 230, 232, 833 are distributed and
connected
so that the floor contains only antennas associated with one branch. A first
branch
floor (i.e. a floor which contains first branch antennas 230) is adjacent to a
second
branch floor (i.e. a floor which contains second branch antennas 232) and is
also
adjacent to a third branch floor (i.e a floor which contains third branch
antennas 833).
At least some of the floors only contain antennas associated with a single
branch. In
the embodiment illustrated, any floors which are not the top floor 102f or the
bottom
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floor 102a include only antennas associated with one branch. That is, any
floors which
are adjacent to two floors, only include antennas associated with a single
branch.
[0092] For example, in the illustrated example, the second floor 102b
contains only
second branch antennas 232 (which are illustrated as being mounted on the
ceiling of
the second floor). Similarly, the third floor 102c is illustrated to contain
only first
branch antennas 233 (which are illustrated as being mounted on the ceiling of
the third
floor) and the fourth floor 102d is illustrated to contain only third branch
antennas 833
(which are illustrated as being mounted on the ceiling of the third floor).
Similarly, the
fourth floor 102d is illustrated to contain only second branch antennas 232
(which are
illustrated as being mounted on the ceiling of the second floor).
[0093] In the example embodiment illustrated, to provide 3x3 MIMO
coverage on
floors which are adjacent to only one other floor (i.e. top floor 102f and the
bottom
floor 102a), antennas associated with two branches have been included on each
of
these two floors. On such floors, the antennas which are included are the
antennas
associated with a branch which is not associated with any antennas on the
adjacent
floor. For example, in the example illustrated the bottom floor includes first
branch
antennas 230 and third branch antennas 833 since the adjacent floor (i.e. the
second
floor 102b) includes second branch antennas 232. Similarly, in the example
illustrated
the top floor 102f includes first branch antennas 230 and third branch
antennas 833
since the adjacent floor (i.e. the fifth floor 102e) includes second branch
antennas 232.
[0094] In other example embodiments (not illustrated), the floors which
are
adjacent to only one other floor (i.e. the top floor 102f and the bottom floor
102a), may
not include antennas associated with more than one branch. Instead, in at
least some
example embodiments, such floors may only include antennas associated with one
branch. In such embodiments, only 2x2 MIMO coverage may be available on such
floors.
[0095] In the example embodiment illustrated, the example methods 400
and 700
of FIGs. 4 and 7 respectively could be modified in order to provide methods
for
providing 3x3 MIMO. For example, the methods 400, 700 may include connecting a
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third branch transport medium coupled to the third branch connector of the 3x3
MIMO
radio 810. Similarly, the methods 400, 700 may include connecting the antennas
distributed on a third branch floor, which is adjacent to a second branch
floor, to the
third branch transport medium. In at least some such embodiments, no antennas
on
the third branch floor are connected to the second branch transport medium or
to the
first branch transport medium and no antennas on a first branch floor (which
contains
first branch antennas) and a second branch floor (which contains second branch
antennas) are connected to the third branch transport medium. That is, the
first branch
floor and the second branch floor do not contain third branch antennas 833.
[0096] The techniques and systems described in the present disclosure may
provide
in-building distributed antenna systems in which branch-groups of antennas are
vertically interleaved. Branch-groups are groups of antennas which may be
associated
with more than one branch. For example, an A-B branch-group of antennas may be
a
group of antennas which contains at least one antenna connected to a first
branch
transport medium 204 (i.e. first branch antennas 230) and at least one antenna
connected to a second branch transport medium 206 (i.e. second branch antennas
232).
[0097] Accordingly, higher order MIMO systems, such as four by four
(4x4), five by
five (5x5), six by six (6x6), and so on, may vertically interleave branch
groups of
antennas.
[0098] By way of example, in at least some example embodiments, a 4x4
MIMO in-
building distributed antenna system could include four branch transport
mediums, each
connecting to a separate branch connecter on a 4x4 MIMO radio. The branches
could
be grouped so that at least some floors include antennas associated with more
than
one branch but at least some floors do not include antennas associated with
all
branches. By way of example, a first branch antenna (i.e. an antenna connected
to the
first branch transport medium) could be grouped with a second branch antenna
(i.e. an
antenna connected to the second branch transport medium). Such a group may be
referred to as an A-B branch group. A third branch antenna (i.e. an antenna
connected
to the third branch transport medium) could be grouped with a fourth branch
antenna
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(i.e. an antenna connected to the fourth branch transport medium). Such a
group may
be referred to as a C-D branch group. The branch groups could be vertically
interleaved
in the structure 100 (FIG. 1) so that floors alternatingly include either an A-
B branch
group or a C-D branch group. For example, every odd numbered floor may include
an
A-B branch group (which includes at least one first branch antenna and at
least one
second branch antenna) and every even numbered floor may include a C-D branch
group (which includes at least one third branch antenna and at least one
fourth branch
antenna). Alternatively, every even numbered floor may include an A-B branch
group
and every odd numbered floor may include a C-D branch group.
[0099] By way of further example, a 5x5 MIMO in-building distributed
antenna
system may include five branch transport mediums, each connecting to a
separate
branch connecter on a 5x5 MIMO radio. The branches could be grouped so that at
least
some floors include antennas associated with more than one branch but at least
some
floors do not include antennas associated with all branches. In some
embodiments,
there may be two branch groups, one which is associated with two branches and
the
other which is associated with three branches.
[00100] By way
of example, a first branch antenna (i.e. an antenna connected to the
first branch transport medium) could be grouped with a second branch antenna
(i.e. an
antenna connected to the second branch transport medium) and a third branch
antenna (i.e. an antenna connected to the third branch transport medium). Such
a
group may be referred to as an A-B-C branch group. A fourth branch antenna
(i.e. an
antenna connected to the fourth branch transport medium) could be grouped with
a
fifth branch antenna (i.e. an antenna connected to the fifth branch transport
medium).
Such a group may be referred to as a D-E branch group. The branch groups could
be
vertically interleaved in the structure 100 (FIG. 1) so that floors
alternatingly include
either an A-B-C branch group or a D-E branch group. For example, every odd
numbered
floor may include an A-B-C branch group and every even numbered floor may
include a
D-E branch group. Alternatively, every even numbered floor may include an A-B-
C
branch group and every odd numbered floor may include a D-E branch group.
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[00101] It will be appreciated that the interleaving of groups could be
extended to
provide in-building distributed antenna system of any MIMO order. For example,
a 6x6
MIMO system could interleave an A-B-C branch group with a D-E-F branch group
and
each floor could alternatingly include one of these two groups.
[00102] The in-building distributed antenna system may also, in at least
some
example embodiments, vertically interleave more than two antenna groups. For
example, in at least some embodiments, three branch groups may be formed and
those
branch groups may be alternatingly included on the floors of a building in a
manner
similar to the manner described with reference to FIG. 8. That is, any floors
which are
adjacent to two other floors could include antennas associated with one branch
group.
The adjacent floors to that floor could each include antennas associated with
one of the
other branch groups.
[00103] In the in-building distributed antenna systems, not all floors
contain
antennas associated with all branches.
However, in at least some example
embodiments, every floor which does not contain an antenna associated with a
given
branch is adjacent to a floor which contains an antenna associated with that
branch. By
not including antennas associated with all branches on all floors, the amount
of cabling
is reduced. However, MIMO communications remain available since all branches
which
are not available on a given floor are available on an adjacent floor.
[00104] In at least some example embodiments, the methods and systems
described
herein may be used to provide an in-building distributed antenna system in an
event
center. The event center may, in various embodiments, be a stadium, arena,
concert
hall or venue or opera house. In at least some embodiments, the event center
may
include a plurality of seating levels. In at least some example embodiments,
an in-
building distributed antenna system may be included in the event center. In
such
embodiments, first branch antennas may be vertically interleaved with second
branch
antennas on a level-wise basis. That is, in at least some embodiments, the
first branch
antennas and the second branch antennas are distributed on alternating levels
of the
event center. Each level may include only antennas associated with one branch.
For
example, a first level (which may be referred to as a 100 level) may include
only
28
CA 02843755 2014-01-31
WO 2013/029145 PCT/CA2011/050520
antennas associated with a first branch and a second level (which may be
referred to as
a 200 level) which is adjacent to the first level, may include only antennas
associated
with a second branch.
[00105] As
discussed above, in at least some of the embodiments described herein,
antennas associated with different branches are separated by a physical
structure or
obstruction. For example, first branch antennas 230 (FIG. 2 & 3) are separated
from
second branch antennas 232 (FIG. 2 & 3) by a floor/ceiling. However, in at
least some
embodiments, the MIMO in-building distributed antenna systems described herein
may
be installed within a structure (such as an event center) which does not
include multiple
floors. That it, in some such embodiments, the first branch antennas and the
second
branch antennas may not have a floor between them. In at least some such
embodiments, first branch antennas may be vertically interleaved with second
branch
antennas by vertically separating the antennas by a sufficient distance. In at
least some
embodiments, first branch antennas are vertically separated from second branch
antennas by at least three meters.
[00106] The various embodiments presented above are merely examples and are in
no way meant to limit the scope of this disclosure. Variations of the
innovations
described herein will be apparent to persons of ordinary skill in the art,
such variations
being within the intended scope of the present application. In particular,
features from
one or more of the above-described embodiments may be selected to create
alternative embodiments comprised of a sub-combination of features which may
not be
explicitly described above. In addition, features from one or more of the
above-
described embodiments may be selected and combined to create alternative
embodiments comprised of a combination of features which may not be explicitly
described above. Features suitable for such combinations and sub-combinations
would
be readily apparent to persons skilled in the art upon review of the present
application
as a whole. The subject matter described herein and in the recited claims
intends to
cover and embrace all suitable changes in
technology.
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