Note: Descriptions are shown in the official language in which they were submitted.
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MULTT-BAND WIFI, CELLULAR AND CATV UPSTREAM SERVICE OVER
CATV NETWORK
CROSS-REFERENCE TO RELATED APPLTCATIONS
[0001] This application claims the benefit of U.S.
Provisional Application No. 60/445,835, filed February
10, 2003, which is incorporated by reference, herein, in
its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to a new system
and topology for providing cellular and WiFi service in
multiple bands by using a cable TV network. The system
can improve the in-building coverage, total available
capacity and high data throughput of different cellular
and WiFi networks, using a single CATV network. The
cellular networks may have multiple air interfaces,
different frequency bands and may be operated,
simultaneously, by different cellular service providers
The WiFi systems can operate, simultaneously by different
standards.
(0003] The new system topology can provide additional
uplink bandwidth to the CATV network thus increasing the
number of CATV subscribers using simultaneously data
services.
[0004] In particular, the invention relates to an
extension to conventional mobile radio networks and WiFi
networks using cable TV or HFC (Hybrid Fiber Coax)
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networks. According to an embodiment, mobile radio
networks and WiFi networks are merged into cable TV
networks to provide improved voice & data services and
coverage, while enhancing network capacity. According to
another embodiment, cable TV networks are used to provide
in-building access for any combination of UMTS, GSM900,
GSM1800, PCS1900, TDMA800, CDMA800 or PDC mobile radio
terminals, in a mobile radio network.
[0005] According to another embodiment, any
combination of UMTS, GSM900, GSM1800, PCS1900, TDMA800,
CDMA800 or PDC type of signals are combined and carried
together on the CATV system, without interfering with
each other, or the CATV service.
[0006] According to another embodiment, cable TV
networks are used to provide in-building access for any
combination of 802.11b, 802.11a WiFi networks.
[0007] According to another embodiment, cable TV
networks are used to provide in-building access for any
combination of UMTS, GSM900, GSM1800, PCS1900, TDMA800,
CDMA800 or PDC mobile radio terminals, in a mobile radio
network together with any combination of 802.11b, 802.11a
WiFi networks.
[0008] According to another embodiment, cable TV
networks are used to provide enhanced uplink capacity to
the CATV networks.
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[0009] According to another embodiment, integration of
multiple air interfaces, different frequency bands
cellular networks, together with multiple WiFi standards
and enhances CATV uplink data services are used to
support full in building coverage with increased capacity
and high data rate.
Related work
[0010] The basic theory by which mobile radio and
cellular networks and WiFi networks operate is well
known. UMTS, GSM, CDMA, TDMA, PDC and 802.11b or
802.11a, 802.118 and 802.11e are examples of a mobile
radio cellular network and WiFi networks.
L0011] Geographically distributed network access
points, each defining cells of the network, characterize
cellular radio networks. The geographically distributed
network access points are typically referred to as base
stations BS or base transceiver stations BTS, and
includes transmission and reception equipment for
transmitting signals to and receiving signals from mobile
radio terminals (MT).
[0012] Each cell (or sector) is using only part of the
total spectrum resources licensed to the network
operator, but the same capacity resources (either
frequency or code, may be used many times in different
cells, as long as the cell to cell interference is kept
to a well defined level. This practice is known as the
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network reuse factor. The cells may be subdivided
further, thus defining microcells. Each such microcell
provides cellular coverage to a defined (and usually
small) area. Microcells are usually limited in terms of
their total available capacity.
[0013] One of the major problems this system can solve
is the inability of present (frequency or code) reuse
techniques (sectorization and cell-area subdivision) to
deal with the 'third dimension' problem. Traditiorial
cellular networks are designed and deployed to provide
mostly outdoors service. Such networks have no means to
deal with the problem of user terminals at higher-than-
usual elevations, e.g. upper floors of high-rise office
or residential buildings.
[0014] The overall demand for both indoor and outdoor
mobile services had caused cellular network operators to
develop an intensive network of BTSs in urban areas.
This has improved spectrum utilization (increased network
capacity) at ground level, but has aggravated the problem
in high-rise buildings where MTs now 'see' several BTSs
on the same frequency or code. Overcoming this problem is
an important aim of the present invention.
[0015] Cells in a cellular radio network are typically
connected to a higher-level entity; known as Mobile
Switching Center (MSC), which provides certain control
and switching functions for all the BTSs connected to it.
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All MSCs are connected to each other, and also to the
public switched telephone network (PSTN), or may
themselves have such a PSTN interface.
[0016] The conventional implementation of UMTS,
GSM1800 or PCS1900 radio networks has had some important
limitations. When operating above lGHz, it is necessary
in a conventional mobile radio network to build numerous
base stations to provide the necessary geographic
coverage and to supply enough capacity for high-speed
data applications. The base stations require an
important amount of real estate, and are very unsightly.
[0017] Another limitation is that, since cellular
towers are expensive, and require real estate and costly
equipment, it is economically feasible to include in a
network only a limited number of them. Accordingly, the
size of cells might be quite large, and it is therefore
necessary to command the mobile radio terminals to
radiate at high-power so as to transmit radio signals,
strong enough for the geographically dispersed cellular
towers to receive.
[0018] As the cell radius becomes larger, the average
effective data rate per user in most packets based
protocols decreases accordingly and the high-speed data
service might deteriorate.
[0019] Yet another limitation to cellular radio
networks as conventionally implemented is that the
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cellular antennas are typically located outside of
buildings, even though it would be highly beneficial to
provide cellular service inside buildings. The
penetration of cellular signals for in-building
applications requires high power sites, or additional
sites or repeaters to overcome the inherent attenuation
inherent with in-building penetration. As frequency
increases, the in-building signal level decreases
accordingly.
[0020] Because the base station antennas are usually
located outside of buildings, it is difficult for mobile
radio terminals to transmit signals strong enough to
propagate effectively from inside of the building to
outside of the building. Therefore, the use of mobile
terminals inside buildings results in reduced data rate
and consumes substantiate amount of the limited battery
time.
[0021] Yet another limitation of UMTS, GSM900,
GSM1800, PCS1900, TDMA800, CDMA800 or PDC radio networks
as conventionally implemented is the inherent limited
capacity of each and every BTS to provide voice and data
service. This capacity shortage is due to the way the
spectrum resources are allocated to each BTS.
[0022] To provide for reasonable voice & data quality,
each BTS can use only a part of the total spectrum
resources owned by the cellular operator. Other BTSs
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could reuse the same part of the spectrum resources as a
given BTS, but a pattern of geographic dispersion would
have to be respected. This is called a code reuse factor
for CDMA based technologies, and frequency reuse factor
for TDMA based technologies.
[0023] The WLAN (WiFi) is a flexible data
communication system implemented as an extension to, or
as an alternative for, a wired LAN. WLAN networks are
designed to support high data rate in building
applications. In a typical Wireless LAN configuration, a
transmitter/receiver device, called an access point,
connects the user wireless device to the wired network
fixed location using standard Ethernet connection (cable,
ADSL, Tl etc.). The access point receives, buffers, and
transmits data between the Wireless LAN and the wired
network infrastructure. A single access point can support
a small group of users and functions within ranges of up
to several hundred feet. End users access the WLAN
through wireless LAN modem device. This is why it is
necessary for a conventional Wireless LAN system to have
an access point at any floor in the building and/or every
100 to 500 feet range, (to provide full coverage and good
receiving signal performance by each of the participants
in order to solve collision problems). This limitation
is related directly to the maximum range that can be
achieved by the conventional Wireless LAN systems.
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[0024] Another limitation is related to the
propagation phenomena that directly affect the data
throughput of the network. The distance over which RF
waves can communicate is a function of the transmitted
power, receiver sensitivity and the propagation path,
especially in indoor environments. Interactions with
typical building objects, including walls, metal, and
even people, can affect the energy propagation, and thus
the range and coverage of a particular system and the
unit's reaction at this specific covered area.
[0025] One way to mitigate the above-identified
disadvantages of conventional mobile networks and WLAN
networks is by using the Access part of a CATV network
for the benefit of the cellular radio network and the
WLAN networks. The CATV network is near-ubiquitous, in
most urban areas. The delivery of cellular signals and
WLAN signals directly to the mobile subscriber's
premises, by using the CATV network, allows reducing the
reuse factor and hence brings an increase of an order of
magnitude in the network's available capacity. This is
due to the fact that the propagation conditions are
greatly improved by using the CATV as an access path
inside buildings, instead of transmitting from outdoor
towers.
[0026] CATV data services to date are growing due to
the demand of new multimedia applications, Internet and
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voice over IP requirements. All these applications are
two-way applications requiring high throughput data both
in upstream and downstream directions. The downstream
capacity of the CATV is large enough to support multi-
simultaneous high data rate users. As the number of the
simultaneous users is growing, the upstream part of the
CATV limits the throughput of the system. Based on
today's architecture the upstream frequency is 5 to 42
MHz, which enables to support 1000 simultaneous users
with 50 Kbps data throughput for each user. Increase in
the requirements for data throughput will reduce the
number of simultaneous users.
SUMMARY OF THE INVENTION
[0027] It is therefore an object to overcome the
above-identified limitations of the present mobile
networks, WLAN networks and Upstream CATV capacity.
[0028] According to one aspect of the system, there is
provided an extension to conventional mobile radio
networks, WLAN networks and enhances upstream CATV,
whereby a CATV network is enabled to transport mobile
radio traffic, WLAN traffic and enhances upstream CATV
traffic. According to another aspect of the system,
there is provided a CATV network capable of handling
traffic in a pre-determined configuration of UMTS,
GSM900, GSM1800,' PCS1900, TDMA800, CDMA800 or PDC,
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802.11b, 802.11a, 802.118, 802.11e, 802.11f (or other
wireless protocols now used or developed hereafter) and
enhanced CATV simultaneously, without degrading the CATV
services.
(0029] To achieve the above and other objects, the
CATV network functions as an access element of the
cellular network, WLAN networks namely in its RF
propagation-radiation section. According to the system
described herein, =the capabilities of existing CATV
networks are substantially preserved. That is to say,
the signals sent according to the radio communications
protocol traverse the CATV network on non-utilized CATV
frequencies (typically 960-2000MHz), but it reaches the
mobile terminals both cellular and WiFi exactly at the
same standard frequency as was originally produced by the
base station.
(0030] The radio frequencies and channel structures of
UMTS, GSM900, GSM1800, PCS1900, TDMA800, CDMA800, PDC,
802.11b or 802.11a, 802.118, 802.11e and the CATV
networks are different. The CATV network is modified so
as to permit the propagation of the RF signals of the
mobile radio network, WLAN networks and CATV upstream
which are frequency translated to propagate over the CATV
system in the 960-2000MHzband.
(0031] This frequency band (960-2000MHz) is not used
at all by the CATV operators, but it may be used to carry
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combinations of UMTS, GSM900, GSM1800, PCS1900, TDMA800,
CDMA800, PDC, 802.11b, 802.11a, 802.11g, 802.11e or CATV
upstream signals by properly upgrading the CATV
infrastructure.
[0032] A conventional CATV network is a two-way
network having a tree and branch topology with cables,
amplifiers, signal splatters / combiners and filters.
According to one aspect of the system, the cables and
other passive components like signal splitters/combiners
are not modified, but the other active elements such as
amplifiers and filters are. Thus, the system includes
new components for a CATV system that permits to overlay
a multi-band, multi-standard, bi-directional
communication system. The modified components allow both
types of signals (the CATV up and down signals, the
cellular up and down signals, and the WLAN up and down
signals) to be carried by the network simultaneously or
in any allowed combination (cellular with WLAN, cellular
with CATV upstream, WLAN with CATV upstream or each of
the above by itself) in a totally independent manner.
[0033] An important aspect of the system described
herein is that the cables (fiber and coaxial) used in
cable TV networks are not severely limited as to
bandwidth. Practical cable TV networks are bandwidth
limited by the bandwidth and signal loading limitations
of practical repeater amplifiers. Cable TV networks now
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use filters to segment cable spectrum into two bands -
one for 'upstream' communications and the other for
downstream 'communications'. By adding duplexers and
filters to provide additional spectrum segmentation it
allows additional amplifiers to handle upstream and
downstream cellular network traffic.
[0034] According to another aspect of the system,
there is provided a integrated up/down converter system
at each LEX amplifier section of the CATV system to
adjust the CATV upgraded frequencies (960 to 2000 MHz) to
the original upstream CATV frequencies 5 to 42 MHz, to
the shifted frequencies of the cellular Passover in door
unit, and to the shifted frequencies of the WLAN Passover
in door unit (see Fig. 2)
[0035] According to another aspect of the system,
there is provided a Passover In Door Unit (PINDU, see Fig
3). The PINDU is a component that acts as a
transmit/receive antenna and frequency translator for any
combination of cellular and the WLAN signals and as a
cable TV input/output unit for the cable TV network.
Most of the existing CATV video signals are already
limited to frequencies under 750MHz (other CATV networks
goes up to 860 MHz) so the standardized cellular signals
are translated to above this limit. The different types
of signals (CATV, Cellular & WLAN) can coexist within the
same coaxial cable~due to this fact.
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[0036] This system modifies the CATV network in a way
that permits the CATV transmissions to be maintained in
their original format and frequency assignments. The
modifications to the CATV network use only linear
components such ' as filters and amplifiers. The
modifications are simple, robust and affordable.
[0037] The invention is taught below by way of various
specific exemplary embodiments explained in detail, and
illustrated in the enclosed drawing~figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] The drawing figures depict, in highly
simplified schematic form, embodiments reflecting the
principles of the invention. Many items and details that
will be readily understood by one familiar with this
field have been omitted so as to avoid obscuring the
invention. In the drawings:
[0039] Fig. 1 shows an example of integrated cellular,
WLAN and CATV site.
[0040] Fig. 2 shows how the sub-bands frequencies
created at the integrated site to be carried on the CATV
network are up/down converted.
[0041] Fig. 3 shows a PINDU configuration where the
CATV upstream and down stream signals are carried on
their original CATV frequencies.
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[0042] Fig. 4 shows a frequency assignment allocation
of the various CATV upstream cellular and WLAN at the
central site.
[0043] Fig. 5 shows another frequency assignment
allocation of the various CATV upstream cellular and WLAN
at the central site.
[0044] Fig. 6 shows frequency assignment of an
integrated Cellular WLAN and CATV upstream network, where
the converted frequencies from the Head End to the CATV
network as described in Fig. 4 and 5 are converted to new
frequencies to be transmitted on the CATV network to a
first group of 500 Homes Passed customer premises PINDUs.
[0045] Fig. 7 shows a frequency assignment of an
integrated Cellular WLAN and CATV upstream network, where
the converted frequencies from the Head End to the CATV
network as described in Fig. 4 and 5 are converted to new
frequencies to be transmitted on the CATV network to the
second group of 500 Homes Passed customer premises
PINDUs.
[0046] Fig. 8 shows a CATV Upstream Frequency Chart
for groups of 500 Homes Passed (HP) (representing full
node of 2000 HP 4X500 HP).
[0047] Fig. 9 shows a WiFi Frequency Chart for groups
of 500 Homes Passed (HP) (representing full node of 2000
HP 4X500 HP) .
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[0048] Fig. 10 shows an example of cellular frequency
allocation for UMTS and GSM 1800 at the customer
premises.
DETAILED DESCRIPTION OF THE INVENTION
(0049] The invention will now be taught using various
exemplary embodiments. Although the embodiments are
described in detail, it will be appreciated that the
invention is not limited to just these embodiments, but
has a scope that is significantly broader. The appended
claims should be consulted to determine the true scope of
the invention.
[0050] Fig. 1 shows an example of integrated cellular,
WLAN and CATV site. The integrated site represents one
node connection. An enlarged system with more than one
node is possible through duplication of the ideas
represented by this specific site. In this example, a
number of cellular operators with the same technology
(GSM 1800) and operators with different technologies are
shown (GSM 1800 and UMTS); any combination of cellular
operator/technologies is relevant. WLAN services based on
802.11a, b, e, g or other can be integrated on the same
network, as well as a number of WLAN access points of the
same network. In this example, upstream CATV signals are
up/down converted to increase node capacity. The figure
shows how the original CATV upstream signals as well as
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the Cellular and WLAN signals are up/down converted and
combined to be carried over the assigned 960 to 2000 MHz
frequencies over the CATV network.
[0051] Fig. 2 shows how the sub-bands' frequencies
created at the integrated site, to be carried on the CATV
network, are up/down converted at each CATV amplifier
section to the (1) original CATV upstream signals; (2)
shifted up/down frequencies of the Passover cellular
indoor unit; and (3) shifted up/down frequencies of the
Passover WLAN indoor unit. Both up-link and downlink
frequencies of the 960 to 2000 MHz segments are
reassigned to 5 to 42 MHz for upstream CATV signals, and
to 960 to 1155 MHz for cellular and WLAN signals to be
carried to the customer premises PINDU, where the shifted
signals will be translated to the original cellular and
WLAN signals.
[0052] Fig. 3 shows a PINDU configuration where the
CATV upstream and down stream signals are carried on
their original CATV frequencies. The other part of the
PINDU describes the up/down converter part of the unit
where cellular and or WLAN signals are converted from 960
to 1155 MHz to the original cellular, WLAN frequencies.
This PINDU can support by duplication of the up/down
portion of the unit number of cellular
operator/technologies as well as number of WLAN
standards.
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[0053] Fig. 4 shows a frequency assignment allocation
of the various CATV upstream cellular and WLAN at the
central site. The frequencies are assigned to be carried
on the CATV network. For example the 5 - 42 MHz upstream
frequency is converted to 4*35 MHz (1300 to 1500 MHz)
thus enables to increase the upstream capacity by 4
times. Other optimal frequency translations can be done
to increase capacity to 10*35 MHz or even 20*35 MHz. In
this case the frequency band required for the upstream
signals will be up to 400 MHz and 800 MHz bandwidth
correspondingly. The decision on the bandwidth is due to.
capacity requirements. The cellular frequencies are
converted. to 75 MHz uplink {1500 - 1575) and 75 MHz
downlink (960 - 1035) to enable up to 7
operators/technologies to operate on the same network. If
additional operators/technologies are required, the
bandwidth can be extended. The WLAN frequencies are
converted to 200 MHz uplink (1600 - 1800) and 200 MHz
downlink {1100 - 1300) to enable up to 4 access points
working together on the same node. If additional access
points are required the bandwidth can be extended.
[0054] Fig. 5 shows another frequency assignment
allocation of the various CATV upstream cellular and WLAN
at the central site. The frequencies are assigned to be
carried on the CATV network. For example the 5 - 42 MHz
upstream frequency is converted to 10*35 MHz (1300 to
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1700 MHz) thus enabling to increase the upstream capacity
by 10 times. The cellular frequencies are converted to 75
MHz uplink (1700 - 1775) and 75 MHz downlink (960 - 1035)
to enable up to 7 operators/technologies to operate on
the same network. The WLAN frequencies are converted to
200 MHz uplink (1800 - 2000) and 200 MHz downlink (1100 -
1300) to enable up to 4 access point working together on
the same node. Other combinations of frequency
assignment Ci.e., other frequency allocation plans) can
be designed based on the capacity requirements of
Cellular, WLAN and CATV upstream signals.
[0055] Fig. 6 shows frequency assignment of an
integrated Cellular WLAN and CATV upstream network, where
the converted frequencies from the Head End to the CATV
network as described in Fig. 4 and 5 are converted to new
frequencies to be transmitted on the CATV network to the
first group of 500 Homes Passed customer premises PINDUs.
For example the first set of the CATV upstream
frequencies 1300 to 1337 MHz is reconverted to the
original CATV upstream frequencies 5 to 42 MHz. The first
set of WLAN uplink and downlink frequencies 1200 to 1220
MHz and 1600 to 1620 MHz are converted to 960 to 980 MHz
and 1080 to 1100 MHz correspondingly. The Cellular
frequencies 960 to 1035 MHz and 1500 to 1575 MHz are
converted to 980 to 1035 MHz (in this case the cellular
frequency bandwidth will be reduced to 980 to 1035 MHz
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decreasing the number of cellular operators /technologies
to 5 scarifying 20 MHz for the WLAN network) and to 1100
to 1155 MHz (in this case the cellular frequency
bandwidth will be reduced to 1100 to 1155 MHz decreasing
the number of cellular operators /technologies to 5
scarifying 20 MHz for the benefit of the WLAN network).
[0056] Fig. 7 shows frequency assignment of an
integrated Cellular WLAN and CATV upstream network, where
the converted frequencies from the Head End to the CATV
network as described in Figs. 4 and 5 are converted to
new frequencies to be transmitted on the CATV network to
the second group of 500 Homes Passed customer premises
PINDUs. For example the second set of the CATV upstream
frequencies 1350 to 1387 MHz is reconverted to the
original CATV upstream frequencies 5 to 42 MHz. The
second set of WLAN uplink and downlink frequencies 1230
to 1250 MHz and 1630 to 1650 MHz are converted to 960 to
980 MHz and 1080 to 1100 MHz correspondingly. The
Cellular frequencies 960 to 1035 MHz and 1500 to 1575 MHz
are converted to 980 to 1035 MHz (in this case the
cellular frequency bandwidth will be reduced to 980 to
1035 MHz decreasing the number of cellular operators
/technologies to 5 scarifying 20 MHz for the WLAN
network) and to 1100 to 1155 MHz (in this case the
cellular frequency bandwidth will be reduced to 1100 to
1155 MHz decreasing the number of cellular operators
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/technologies to 5 scarifying 20 MHz for the benefit of
the WLAN network).
[0057] Fig. 8 chows, CATV Upstream Frequency Chart for
groups of 500 Homes Passed (HP) (representing full node
,of 2000 HP 4X500 HP), The Upstream signals 5 - 42 MHz
coming from the Cable Modem (CM) at the customer premises
for each group of 500 Homes Passed (HP) is converted at
the LEX Amplifier junction to 1300-1337 MHz, 1350 - 1387
MHz, 1400 - 1437 MHz and 1450 - 1487 MHz correspondingly.
This set of frequencies is transmitted on the CATV
network to be received by the Up/Down Converter (UDC) at
the integrated site . At the integrated site the received
signals by the UDC are down converted back to 5 - 42 MHz
to be integrated into the CMTS (Cable Modem Terminal
System) .
[0058] Fig. 9 shows a WiFi Frequency Chart for groups
of 500 Homes Passed (HP) (representing a full node of
2000 HP, 4X500 HP) . The frequency chart is an example of
the 802.11b standard, any other 802.11 standard like
802.11a, e.g., or Hyper-WLAN is applicable. Other
wireless standards developed hereafter will also be
applicable. The Access point TDD signals at 2412 MHz ~ 10
MHz are converted to 1100 - 1120 MHz, 1130 - 1150 MHz,
1160 - 1180 MHz, 1190 - 1210 MHz downlink signals and to
1600 - 1620 MHz, 1630 - 1650 MHz, 1660 - 1680 MHz, 1690 -
1710 MHz uplink signals correspondingly. This set of
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frequencies is transmitted over the CATV network. At each
LEX amplifier junction the uplink and downlink
frequencies are converted to 960 - 980 MHz downlink and
1080 - 1100 MHz uplink signals to be carried to the 500
HP customer premises, entering the customer PINDU. If the
number of simultaneous WiFi users is increased,
additional access points can be added to the system and
the frequency band may be increased to support additional
access points. At the customer premises, the PINDU
reconverts the WiFi signals to their original signals
2412 MHz + 10 MHz to be transmitted at the customer
premises. The frequency bandwidth allocated to the WiFi
and the cellular systems can be adjusted according to the
network requirements and design.
[0059] Fig. 10 shows an example of cellular frequency
allocation for UMTS and GSM 1800 at the customer
premises. Other cellular systems like GSM 900, PCS and
others can be incorporated into the frequency band. The
frequency band assigned to the cellular will be adjusted
to fit both WLAN and cellular. This set of frequencies
960 - 1035 MHz downlink and 1080 - 1155 MHz uplink is
converted from 960 - 1035 MHz downlink and 1500 - 1575
MHz coming from the CATV network. The 960 - 1155 MHz
frequencies at the PINDU customer premises and at the UDC
are reconverted to the original cellular frequencies to
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be transmitted to the customer cellular terminal unit and
to the Base Station.
[0060] Many variations to the above-identified
embodiments are possible without departing from the scope
and spirit of the invention. Possible variations have
been presented throughout the foregoing discussion.
Moreover, it will be appreciated that combinations and
subcombinations of the various embodiments described
above will occur to those familiar with this field,
without departing from the scope and spirit of the
invention. For example, the provision of WLAN service
over a CATV network using switching mode PCF can be
integrated into the foregoing approaches, including the
conversion of TDD WLAN signals to FDD, as described in
the provisional application entitled WLAN SERVICES OVER
CATV NETWORK USING SWITCHING MODE PCF PROTOCOL, filed on
the February 10, 2003, by the same inventors,
incorporated herein by reference in its entirety for its
teaching thereon.
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