U.S. patent application number 15/005450 was filed with the patent office on 2016-05-19 for multiple data services over a distributed antenna system.
The applicant listed for this patent is Corning Optical Communications Wireless Ltd.. Invention is credited to Ofer Saban, Isaac Shapira.
Application Number | 20160142196 15/005450 |
Document ID | / |
Family ID | 41319113 |
Filed Date | 2016-05-19 |
United States Patent
Application |
20160142196 |
Kind Code |
A1 |
Saban; Ofer ; et
al. |
May 19, 2016 |
MULTIPLE DATA SERVICES OVER A DISTRIBUTED ANTENNA SYSTEM
Abstract
Supporting multiple time division duplexed (TDD) based wireless
services or frequency division duplexed (FDD) wireless services on
a Distributed Antenna System (DAS). TDD based services use a common
clock signal to synchronize the components of the DAS for
transmission and reception of TDD signals. The DAS can include a
GPS receiver which can extract a timing signal from a GPS signal
and distribute the timing signal to any and all components of the
DAS to enable synchronization of the components for transmitting
and receiving TDD signals. The GPS receiver can be part of the
interface that connects a TDD based service to the DAS or separate
component of the DAS. The DAS can distribute a reference clock
signal to all of the components of the DAS in order to maintain
zero frequency shift while manipulating with the carrier
frequencies of the various wireless services carried by the
DAS.
Inventors: |
Saban; Ofer; (Vienna,
VA) ; Shapira; Isaac; (Petach Tikva, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Corning Optical Communications Wireless Ltd. |
Airport City |
|
IL |
|
|
Family ID: |
41319113 |
Appl. No.: |
15/005450 |
Filed: |
January 25, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13440173 |
Apr 5, 2012 |
9246557 |
|
|
15005450 |
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12465288 |
May 13, 2009 |
8195224 |
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13440173 |
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61052851 |
May 13, 2008 |
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Current U.S.
Class: |
370/328 ;
370/350 |
Current CPC
Class: |
H04W 88/085 20130101;
H04L 5/14 20130101; H04W 28/0226 20130101; H04B 7/024 20130101 |
International
Class: |
H04L 5/14 20060101
H04L005/14; H04B 7/02 20060101 H04B007/02; H04W 28/02 20060101
H04W028/02; H04W 88/08 20060101 H04W088/08 |
Claims
1. A wireless system, comprising: at least one wireless source
coupled to at least one wiring unit, the at least one wireless
source providing signals corresponding to a first wireless service
over the wireless system; a plurality of cable runs each including
electrical radio frequency conducting media and connecting the at
least one wiring unit to a plurality of antenna units, each antenna
unit having at least one duplexer and at least one deduplexer, the
cable runs connecting the at least one wiring unit to at least one
of the antenna units and transferring signals corresponding to at
least one wireless service between the at least one wiring unit and
at least one of the antenna units; an interface adapted to connect
a second wireless source providing a second wireless service to the
wireless system and transfer signals corresponding to the second
wireless service over the wireless system; and an envelope detector
connected to the wireless system and adapted to receive a signal
corresponding to the wireless service and to produce a timing
signal, the timing signal being transferred over the wireless
system.
2. The wireless system of claim 1, further comprising the second
wireless source connected to the interface.
3. The wireless system of claim 2, wherein the envelope detector is
connected to the second wireless source and adapted to transfer the
timing signal to the interface.
4. The wireless system of claim 3, wherein the timing signal is
transferred over the wireless system to at least one of the antenna
units and used by the antenna unit to synchronize an operation of
the antenna unit.
5. The wireless system of claim 2, wherein the timing signal is
modulated onto a carrier signal and transferred over the wireless
system using the carrier signal.
6. A wireless system, comprising: a first combining unit; a
plurality of cable runs each including electrical radio frequency
conducting media and connecting the first combining unit to a
plurality of antenna units, each antenna unit having at least one
duplexer and at least one deduplexer; the first combining unit
including a base station connection capable of connecting a base
station to the first combining unit, the first combining unit being
capable of transferring signals corresponding to a first wireless
service between the base station and at least one of the cable
runs; at least one wireless service access point connected to the
first combining unit, the first combining unit being capable of
transferring signals corresponding to a second wireless service
between the at least one wireless access point and at least one of
the cable runs; a first interface module connected to the wireless
service access point and capable of converting a control signal
sent from the wireless service access point to an intermediate
frequency (IF) control signal and transferring the IF control
signal between the wireless service access point and the first
combining unit; and a second combining unit connected to at least
one of the cable runs and capable of receiving the IF control
signal and converting the IF control signal back to the control
signal and transferring the control signal to at least one of the
antenna units of the wireless system.
7. The wireless system of claim 6, further comprising a reference
clock signal generator connected to the first combining unit and
capable of generating a reference clock signal, the first combining
unit being capable of receiving the reference clock signal and
transmitting the reference clock signal over at least one of the
cable runs to at least one of the antenna units.
8. The wireless system of claim 7, wherein the first combining unit
is capable of transferring the IF control signal between the first
interface module and at least one of the cable runs, and uses the
reference clock signal to convert a signal received from the access
point corresponding to the second wireless service to an
intermediate frequency signal and transfers the intermediate
frequency signal over at least one of the cable runs to at least
one of the antenna units.
9. A wireless system comprising: at least one wiring unit; a first
wireless source connected to the at least one wiring unit, the
first wireless source providing signals corresponding to a first
wireless service over the wireless system; a plurality of antenna
units, each antenna unit having at least one duplexer and at least
one deduplexer; a plurality of cable runs each including electrical
radio frequency conducting media connecting the at least one wiring
unit to the plurality of antenna units and transferring signals
corresponding to at least one wireless service between the at least
one wiring unit and the antenna units; a second wireless source; an
interface adapted to connect the second wireless source to provide
a second wireless service to the wireless system and transfer
signals corresponding to the second wireless service over the
wireless system; and an envelope detector system adapted to produce
a timing signal, the timing signal being transferred over the
wireless system, wherein the envelope detector system is connected
to the second wireless source and adapted to transfer the timing
signal to the interface.
10. A wireless system comprising: at least one wireless source
connected to a main wiring closet unit, said at least one wireless
source producing signals corresponding to a first wireless service
over the wireless system; a remote wiring closet unit connected to
the main wiring closet unit, the remote wiring closet unit
including at least one combining unit, the at least one combining
unit being adapted to transfer signals corresponding to two or more
wireless services between the at least one wireless source and at
least one cable run to an antenna unit; at least one cable run
connecting the at least one combining unit to at least one antenna
unit to transfer the signals corresponding to the first wireless
service over the wireless system; an interface adapted to connect a
second wireless service to the wireless system and transfer signals
corresponding to the second wireless service over the wireless
system; and an envelope detector system connected to the wireless
system and adapted to produce and send a timing signal over the
wireless system.
11. A wireless system according to claim 10, wherein the interface
is connected to the remote wiring closet unit and adapted to
transfer signals corresponding to the second wireless service over
the DAS.
12. A wireless system according to claim 11, wherein the interface
is connected to the at least one antenna unit and adapted to
transfer signals corresponding to the second wireless service over
the at least one antenna unit.
13. A wireless system comprising: at least one wireless source
coupled to at least one wiring closet unit, said at least one
wireless source providing signals corresponding to a first wireless
service over the wireless system; at least one antenna unit
comprising at least one duplexer and at least one deduplexer; at
least one cable run connecting the at least one wiring closet unit
to at the least one antenna unit and transferring signals
corresponding to at least one wireless service between the at least
one wiring closet unit and at least one antenna unit; an interface
adapted to connect a second wireless source providing a second
wireless service to the wireless system and transfer signals
corresponding to the second wireless service over the wireless
system; and an envelope detector connected to the wireless system
and adapted to receive a signal corresponding to a wireless service
and produce a timing signal, said timing signal being transferred
over the wireless system, wherein the timing signal is modulated
onto a carrier signal and transferred over the wireless system to
the at least one antenna unit using the carrier signal, and used by
the antenna unit to synchronize an operation of the antenna unit.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 13/440,173, now U.S. Pat. No. 9,246,557, filed
Apr. 5, 2012, which is a continuation of U.S. patent application
Ser. No. 12/465,288, filed on May 13, 2009, now U.S. Pat. No.
8,195,224, which claims the benefit of priority under 35 U.S.C.
.sctn.119 of U.S. Provisional Patent App. No. 61/052,851, filed on
May 13, 2008, the contents of which are relied upon and
incorporated herein by reference in their entireties.
[0002] This application is related to the following: U.S. patent
application Ser. No. 11/958,062, now U.S. Pat. No. 8,873,585, filed
Dec. 17, 2007, Ser. No. 12/016,459, now U.S. Pat. No. 8,121,646,
filed Jan. 18, 2008, Ser. No. 12/016,477, filed Jan. 18, 2008, Ser.
No. 12/033,226, filed Feb. 19, 2008 and Ser. No. 12/033,252, filed
Feb. 19, 2008, which are hereby incorporated by reference in their
entireties.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0003] Not Applicable
REFERENCE TO MICROFICHE APPENDIX
[0004] Not Applicable
BACKGROUND
[0005] 1. Technical Field of the Invention
[0006] The present invention is directed to Distributed Antenna
Systems (DASs) and more particularly, to methods and systems for
supporting multiple wireless data services on a DAS.
[0007] Distributed Antenna Systems are used to provide or enhance
coverage for wireless services such as Public Safety, Cellular
Telephony, Wireless LAN and Medical Telemetry inside buildings and
over campuses. The general architecture of a DAS is depicted in
FIG. 1.
[0008] A single DAS can serve a single wireless service or a
combination of many wireless services operating over multiple
bands. With respect to each wireless service served by the DAS, the
Aggregation Configuration of the wireless service can be
characterized as non-aggregated or aggregated. In a non-aggregated
configuration, there is a 1:1 relationship between DAS antennae and
Base Transceiver Stations (BTS) or Transmitter/Receiver units for
that wireless service. In an aggregated configuration, each BTS
unit for a given wireless service is associated with multiple DAS
antennae through a hierarchy of aggregation. For example, in FIG.
2, Services A, B, and C are aggregated and Services D1, D2, and D3
are non-aggregated. Services such as D1, D2, and D3 can be
aggregated as well. The ability to aggregate services is typically
a function of the remote wiring closet equip. Typically, wireless
LAN services are arranged in a non-aggregated configuration when
using a DAS while cellular services are typically arranged in an
aggregated configuration.
[0009] One desired characteristic of a multi-service DAS is that it
can use a single antenna to radiate and receive the signals for all
services and frequency bands supported by the DAS. Such an antenna
would need to cover (i.e. have acceptable performance) in all
frequency bands of interest and is commonly referred to as a
Broadband Antenna. An example of a supported frequency range for a
DAS antenna would be 400 MHz-6 GHz. To provide MIMO based services,
a MIMO antenna which includes multiple antenna elements at a common
location can be used.
[0010] In referring to the signal flows in DAS systems, the term
Downlink signal refers to the signal being transmitted by the
source transmitter (e.g. cellular base station) through an antenna
to the terminals and the term Uplink signal refers to the signals
being transmitted by the terminals which are received by an antenna
and flow to the source receiver. Many wireless services have both
an uplink and a downlink, but some have only a downlink (e.g. a
mobile video broadcast service) or only an uplink (e.g. certain
types of medical telemetry).
[0011] 2. Description of the Prior Art
[0012] In addition to providing cellular and other wireless
services, these DAS can be used to provide Time Division Duplexed
(TDD) based services such as WiFi (IEEE 802.11 and similar
standards), ZigBee, Blue Tooth, WiMAX, Advanced Wireless Services
(AWS) as well as Frequency Division Duplex (FDD) based services
such as WiMAX, Personal Communication Services (PCS) and AWS. When
a DAS used to provide these services, either the Main wiring closet
or remote wiring closet equipment needs an interface to connect the
service network to the DAS. These source interfaces are commonly
referred to as a Macro/Micro/Pico/Femto BTS or Access Point (AP)
etc. For each additional wireless service that is connected to the
DAS a separate, dedicated BTS is needed. Thus, it is difficult to
support multiple service networks on a DAS because many expensive
BTS devices are needed.
SUMMARY
[0013] One of the benefits of a DAS is that it can allow many
different wireless services to be provided over a common physical
infrastructure (wiring, wiring closet units, antenna units and
other physical components). Thus, once the physical infrastructure
is installed, the same physical infrastructure can be used to
support additional wireless services and avoids the expense of
additional equipment and the installation of that equipment. In
addition, operational benefits include lower energy costs and
potentially lower maintenance costs.
[0014] Where a DAS has been installed in a facility, it can be
desirable to add other wireless services including TDD based
services such as WiFi, WiMAX, AWS, ZigBee, Blue Tooth and FDD based
services such as WiMAX, PCS and AWS. For each service, an interface
can be used to connect the service network to the DAS. In addition,
a GPS receiver (or an envelope detector) can be connected to the
DAS and used to provide a 1 pulse per second (1 pps) signal to
synchronize any and all of the components of the DAS for
transmitting and receiving the wireless signals. The 1 pps signal
can be distributed over the DAS to any or all of the wiring closet
units and to the antenna units to enable them to be synchronized
for transmission and reception of the wireless signal.
[0015] In accordance with one embodiment of the invention, the DAS
includes a BTS coupled to one or more wiring closet or combining
units, each wiring closet unit being coupled to one or more antenna
units for providing a wireless service. The antenna units can
include passive or active antenna elements or a combination of
both. The DAS can be coupled to a first interface which is coupled
to a first wireless network to enable the DAS to carry the first
wireless network signals over the DAS and the DAS can also be
coupled to a second interface which is coupled to a second wireless
network to enable the DAS to carry the second wireless network
signals over the DAS. All the active elements in the DAS can be
monitored or configured by a point to multipoint centralized
management system, the management system can transmit and receive
point to multipoint signals to and from any of the addressed
elements attached to the DAS. The DAS can also coupled to a global
positioning system (GPS) receiver and adapted to receive the 1 pps
clock signal from one or more GPS satellites and the DAS is adapted
and configured to distribute the 1 pps signal to any or all the
BTS, wiring closet or combining units and antenna units of the
DAS.
[0016] In some embodiments of the invention, the GPS receiver can
be integrated with one or more of the interfaces. In alternative
embodiments, the GPS receiver can be integrated with the BTS. In
alternative embodiments, the GPS receiver can be a separate
component connected to any one of the BTS, the first interface, the
second interface, the wiring closet units, combining units or the
antenna units. In an alternative embodiment, the first interface
can include a BTS. In an alternative embodiment, the second
interface can include a BTS.
[0017] In accordance with another embodiment of the present
invention, the DAS can include a BTS coupled to one or more wiring
closet units, each wiring closet unit being coupled to one or more
antenna units for providing a first TDD wireless service. The DAS
can be coupled to a second interface which is coupled to a second
TDD network to enable the DAS to carry the second TDD network
signals over the DAS. The DAS can also be coupled to a global
positioning system (GPS) receiver and adapted to receive the 1 pps
clock signal from one or more GPS satellites and the DAS can be
adapted and configured to distribute the 1 pps signal to any or all
the BTS, wiring closet units and antenna units of the DAS.
[0018] In some embodiments of the invention, the GPS receiver can
be integrated in the BTS. In alternative embodiments, the GPS can
be integrated into the second interface. In alternative
embodiments, the GPS receiver can be a separate component connected
to any one of the BTS, the second interface, the wiring closet
units or the antenna units. In an alternative embodiment, the
second interface can include a BTS.
[0019] In some embodiments of the invention, the GPS RF signal
(e.g., 1.5 Ghz) can be, for example, multiplexed with the other
services, and distributed over the DAS without extracting the 1 PPS
signal. The GPS RF signal can be de-multiplex and fed to the BTS
that includes a GPS receiver or other external GPS receiver at the
remote or antenna location.
[0020] In accordance with one embodiment of the invention, instead
of a GPS receiver, the DAS can include an envelope detector adapted
to extract or recover a 1 pps signal from a TDD signal received by
one of the interfaces (for example: Micro cells, Pico cells or
Femto cells). The envelope detector can be adapted and configured
to extract or recover the 1 pps signal and transfer it to the DAS
for distribution to any or all of the components of the DAS
including the BTSs, the other interfaces (including other Pico or
Femto cells), the wiring closet or combining units, and the antenna
units.
[0021] In accordance with one embodiment of the invention, the DAS
can be adapted to distribute the 1 pps signal to any and all
components of the DAS. The GPS receiver can include or be coupled
to a modem or modulator adapted for modulating the 1 pps signal
onto a carrier signal and transmitting the carrier signal to any
and all components of the DAS. The components of the DAS, including
the BTS, the main closet unit, the wiring closet units and the
antenna units can include or be coupled to a modem or demodulator
adapted for demodulating and extracting the 1 pps signal from the
carrier signal and transferring the 1 pps signal to any and all
components of the DAS for use in transmitting and receiving TDD
signals. The 1 pps signal can be carried on a carrier signal that
is distributed over the physical infrastructure of the DAS. Each
antenna unit can include a signal processor adapted and configured
to regenerate, extract or recover the 1 pps signal from the carrier
signal. The carrier signal can be generated at any frequency that
the DAS is capable to deliver preferably on non occupied bands, for
example, for wired links, using bands below 100 MHz. such as the
20-50 MHz bands and for optical links, using bands over 1 GHz, such
as the 1.2-1.7, 2.7-3.0 GHz bands.
[0022] In accordance with one embodiment of the invention, the GPS
receiver can be coupled to one or more of the wiring closet units
and adapted to transfer the 1 pps signal to one or more of the
wiring closet units. The wiring closet units can transmit the 1 pps
signal over the (wire and/or optical) cable infrastructure
connecting the components of the DAS. The 1 pps signal can be used
by the components of the DAS for transmitting and receiving TDD
signals.
[0023] In accordance with an embodiment of the invention, the DAS
can include a component for generating a reference clock signal,
such as an OCXO clock or a pilot clock signal. Typically the
reference clock signal will be a 10 Mhz-20 Mhz clock signal. The
reference clock signal can be transferred to any and all of the
components of over the DAS. The reference clock signal can carried
on a 1.5 Ghz-2.0 Ghz carrier signal that is distributed over the
physical infrastructure of the DAS. Each component of the DAS can
include a Phase Lock Loop (PLL) based component that is adapted and
configured to regenerate, extract or recover the reference clock
signal from the carrier signal. In some embodiments of the
invention, the clock can be delivered at a high frequency (1.5-3
GHz) in order to reduce the potential to introduce noise or
interferences to other services and particularly where the
communication medium includes an optical communication medium. In
some embodiments of the invention, where the communication medium
includes a coaxial cable the original clock frequency 10-20 MHz can
be used to deliver the reference clock signal.
[0024] One object of the invention is to provide a DAS which can
support many wireless services at the same time.
[0025] Another object of the invention is to provide a DAS which
can support many wireless services at the same time at a low
cost.
[0026] Another object of the invention is to provide a DAS which
can support many TDD and FDD based wireless services at the same
time.
[0027] Another object of the invention is to provide a DAS which
can support many TDD and FDD based wireless services at the same
time at a low cost.
[0028] Another object of the invention is to provide a DAS which
can support many TDD based wireless services at the same time using
the same TDD amplifier where all of the TDD based wireless services
can be synchronized to the same TDD timing signal.
[0029] The present invention can be applied to single service and
multi-service DAS, in both aggregated and non-aggregated
configurations and to both downlink and uplink signal flows.
[0030] These and other capabilities of the invention, along with
the invention itself, will be more fully understood after a review
of the following figures, detailed description, and claims.
BRIEF DESCRIPTION OF THE FIGURES
[0031] FIG. 1 is a block diagram of a DAS according to the
invention.
[0032] FIG. 2 is a block diagram of a DAS according to the
invention.
[0033] FIG. 3 is a block diagram of a DAS according to one aspect
of the invention.
[0034] FIG. 4 is a block diagram of a DAS according to one aspect
of the invention.
[0035] FIG. 5 is a block diagram of a DAS according to one aspect
of the invention.
[0036] FIG. 6 is a block diagram of a DAS according to one aspect
of the invention.
[0037] FIG. 7 is a block diagram of an interface according to one
aspect of the invention.
[0038] FIG. 8 is a block diagram of a DAS according to one aspect
of the invention.
[0039] FIG. 9 is a block diagram of a DAS according to one aspect
of the invention.
[0040] FIG. 10 is a block diagram of a DAS according to one aspect
of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0041] The present invention is directed to a method and system for
carrying wireless services over a distributed antenna systems
(DASs). In accordance with one embodiment of the invention, the DAS
includes an interface that connects each wireless service to the
DAS and enables the wireless service signals to be transferred
through the DAS. The system also includes a GPS receiver (or
envelope detector) which is adapted and configured to receive a 1
pulse per second (1 pps) synchronization signal used to control the
timing of the wireless signals, such as TDD based signal. The DAS
can be adapted and configured to transfer the 1 pps signal to
various components of the DAS to enable the DAS to support the
transfer of the wireless signals through the DAS. The system can
also include a reference clock generator for generating a reference
clock signal. The DAS can be adapted and configured to distribute
the reference clock signal to any and all components of the DAS.
The reference clock signal can be used to synchronize the frequency
conversion components of the DAS that change the frequency of the
carrier signals (up-shifting or down-shifting the carrier
frequency) of the signals carried through the DAS.
[0042] The DAS can also utilize a control channel to send control
and configuration information to and receive status information
from each managed component of the DAS. The control channel can
utilize one or more of the unutilized frequency bands or channels
of the DAS to send and receive signals used to carry information
between components of the DAS. The control channel can use
different frequency bands or channels depending on the
communication medium used to convey the signals. For example, the
control channel can use a channel in the 80 MHz band over wired
media and a channel in the 400 MHz band over optical media. The DAS
can use frequency-shift keying (FSK) or amplitude-shift keying
(ASK) as the modulation scheme to carry data over the DAS. A DAS
management system connected to the main wiring closet or the remote
wiring closet can communicate with each managed component of the
DAS using a unique address assigned to the component.
[0043] In accordance with the invention, the DAS can provide a
single wireless service or multiple wireless services. With respect
to systems providing multiple wireless services, the invention can
provide a 1 pps timing signal and/or a 10-20 Mhz clock signal to
any or all of the components of the DAS that are used to transfer
the signals used by wireless services. In some embodiments of the
invention, the 1 pps timing signal can be derived from a GPS signal
using a GPS receiver. In alternate embodiments of the invention,
the 1 pps timing signal can be detected or derived from one or more
of the TDD signals using a hardware or software envelope detector
system. The invention can use software in its implementation and
the method according to the invention can be software controlled
and completely automated.
[0044] As shown in FIG. 3, the system 300 according to the
invention can include in a remote wiring closet 310, one or more
aggregation units 312, one or more wiring closet or combining units
314, one or more RF/IF interfaces 316, and one or more wireless
network service interfaces, Sources Dn 320. The system 300 can also
include one or more BTS systems (shown in FIG. 2) providing
wireless services, a main closet unit (shown in FIG. 2) for
distributing signals corresponding to the wireless services, one or
more cable runs 340 and one or more antenna units 350. The system
300 can also includes a 1 pps timing signal. As shown in FIG. 3,
the system 300 can include a GPS receiver 330 which is adapted to
receive a GPS signal and extract a 1 pps timing signal, for
example, from the 1.5 GHz GPS timing signal (the GPS signal can be
obtained from an external antenna directly or from the main closet,
multiplexed with the other services). The GPS receiver 330 can be
connected to the DAS and the DAS can be adapted to transfer the 1
pps timing signal to any and all components of the DAS. In some
embodiments of the invention, the GPS timing signal (either 1 pps
or 1.5 GHz) can be connected to that DAS at the main wiring closet
and distributed to any and all remote wiring closet units 314 for
distribution to the antenna units. In other embodiments of the
invention, a separate GPS timing signal source can be connected to
each remote wiring closet unit 314 for distribution to the antenna
units 350, although all remote wiring closet units 314 need not be
connected to a GPS timing signal source. Also shown in FIG. 3, the
system 300 can include a reference clock source 318 which can be
used to generate a reference timing signal for up converting or
down converting (i.e. changing the frequency of) the carrier
signals used to transfer the various services through of the
DAS.
[0045] In accordance with one embodiment of the invention, the GPS
receiver 330 can be connected to one or more of the aggregation
units 312. Each aggregation unit can received one or more signals
corresponding to two or more wireless services and can combine the
signals from two or more wireless services for transfer over the
cable run 340 to one or more antenna units 350. Each aggregation
unit 312 connected to the GPS receiver can include a modem or
modulator for modulating the 1 pps signal onto a predefined carrier
signal which can be transmitted to other components of the DAS. The
carrier signal can be, for example, a 100 Mhz carrier signal that
is transmitted over the physical infrastructure (i.e., the cables
and components) of the DAS. For example, one or more of the antenna
units 350 can include a modem or demodulator for demodulating the 1
pps timing signal and recovering it from the predefined carrier
signal. The 1 pps timing signal can be used by the TDD switching
mechanisms, the duplexers and deduplexers of the antenna units to
synchronize the operation of some or all of the components of the
antenna unit with the TDD signal. Alternatively, the DAS can
include additional cabling and physical components for transferring
the 1 pps timing signal to other components of the DAS.
[0046] The GPS receiver 330 can also be connected to the network
service interfaces, Source Dn 320 to provide the 1 pps signal for
use in processing the network service signals. Alternatively, the
GPS receiver 330 can provide the 1.5 Ghz GPS signal directly to the
Source Dn 320 which can use an internal GPS receiver to extract or
recover the 1 pps signal by de-multiplexing the GPS signal provided
by the other services that run over the DAS from the main wiring
closet. Alternatively, the GPS receiver can be replaced by an
envelope detector system which processes or analyzes the TDD signal
received by Source Dn 320 and extracts or recovers the 1 pps
signal. The 1 pps signal determined by the envelope detector system
can be further distributed to all the components of the DAS as
described herein. Alternatively, the 1.5 GHz or 1 pps GPS timing
signal can be provided at the main wiring closet and distributed to
each component over the DAS. The components can include a
demultiplexer to demultiplex the GPS timing signal from the other
services for use by the component.
[0047] While FIG. 3 shows the GPS receiver 330 as a separate
component, the GPS receiver 330 can be integrated with the Source
Dn 320 as shown in FIG. 7. In addition, the 1 pps timing signal can
be used to provide a timing signal for many different TDD and other
synchronized services. The 1 pps timing signal can be converted to
a different frequency and used to synchronize other wireless
services that require a synchronized clock signal, including
non-TDD based wireless services.
[0048] The reference clock re generator source 318 can include a
phase locked loop (PLL) and generate a reference timing signal that
can be distributed over the associated DAS components and BTS. The
reference timing signal can be, for example, a 10-20 MHz timing
signal. The clock can be distributed over the DAS at high
frequency, 1-3 GHz, in order to avoid the introduction of noise or
interference in other services provided by the DAS.
[0049] FIG. 4 shows a system 400 according to an alternate
embodiment of the invention. Similar to FIG. 3, system 400 can
include one or more BTS systems 402 providing wireless services, a
main closet unit 408 for distributing signals corresponding to the
wireless services to wiring closet units, a remote wiring closet
410 including one or more wiring closet units that can combine the
signals from two or more wireless services, Source 1 interface 422,
Source 2 interface 424, and Source 4 interface 426 which provide
interfaces to other wireless services provided by the DAS. The
system 400 can also include a reference clock source 404 which
produces a reference timing signal. As shown in FIG. 4, the system
400 can include a reference clock source 404 which is adapted to
produce a predefined reference timing signal which can be fed into
the main wiring closet and distributed over DAS. The system 400 can
also include a GPS receiver (not shown) that can be connected to
one or more of the BTS systems or wireless network service sources
Source 1 422, Source 2 424, Source 3 426 of the DAS and the DAS can
be adapted to transfer the 1 pps timing signal to any and all
components of the DAS as described herein. The GPS receiver can be
a separate component or it can be integrated with one or more of
the components of the system 300. Each of the wireless service
sources Source 1 422, Source 2 424, Source 3 426 can be connected
by wire or by a wireless connection (repeater not shown) to a
network that carries the network traffic for that wireless
service.
[0050] FIG. 5 shows a DAS 500 according to an alternate embodiment
of the invention. Similar to FIGS. 3 and 4, DAS 500 can include one
or more BTS systems 502 providing wireless services, a main closet
unit 508 for distributing signals corresponding to the wireless
services to wiring closet units, a remote wiring closet 510
including one or more wiring closet units that can combine the
signals from two or more wireless services, Source 1 522, Source 2
524, and Source 3 526 which provide interfaces to other wireless
services provided over the DAS. The system 500 can also include a
reference clock source 504 which produces a reference timing
signal. The system 500 can also include a 1 pps timing signal. As
shown in FIG. 5, the system 500 can include a GPS receiver 530
which is adapted to receive a GPS signal an extract a 1 pps timing
signal. The GPS receiver 530 can be connected to one or more of the
Source 1, 2 or 3 units 522, 524, 526 of the DAS and the DAS can be
adapted to transfer the 1 pps timing signal to any and all
components of the DAS as described herein. While FIG. 5 shows the
GPS receiver 530 as a separate component, a GPS receiver 530 can be
integrated with one or more of the Source 1, 2, 3 units 522, 524,
and 526 as shown in FIG. 7 below.
[0051] FIG. 6 shows a DAS 600 according to an alternate embodiment
of the invention. Similar to FIGS. 3, 4 and 5, DAS 600 can include
one or more BTS systems 602 providing wireless services, a main
closet unit 608 for distributing signals corresponding to the
wireless services to wiring closet units, a remote wiring closet
610 including one or more wiring closet units that can combine the
signals from two or more wireless services, Source 1 622, Source 2
624, and Source 3 626 which can provide interfaces to other
wireless services provided over the DAS. The system 600 can also
include a reference clock source 604 which produces a reference
timing signal. The system 600 also includes a 1 pps timing signal.
As shown in FIG. 6, the system 600 can include a GPS receiver 630
which is adapted to receive a GPS signal an extract a 1 pps timing
signal. The GPS receiver 630 can be connected to one or more of the
antenna units 650 of the DAS and the DAS 600 can be adapted to
transfer the 1 pps timing signal to any and all components of the
DAS 600 as described herein. While FIG. 6 shows the GPS receiver
630 as a separate component, a GPS receiver 630 can be integrated
with one or more of the antenna units.
[0052] FIG. 7 shows a block diagram of a Source or interface unit
700 in accordance with an embodiment of the present invention. The
interface unit 700 can include a radio frequency front end (RF FE)
702, a reference clock source 704, a broad band signal processor
(BB Processor 706, an Internet Protocol Interface (IP Interface)
708 and a CPU 712. Interface unit 700 can optionally include a GPS
receiver 730 for receiving GPS signals and producing a 1 pps timing
signal. The RF FE 702 can be connected either directly or
indirectly to one or more antennae and adapted for transmitting and
receiving one or more RF signals. The interface unit 700 can
include one or more different types of RF FEs 702, including a MIMO
RF FE, a CDMA RF FE, a TDD RF FE and a GSM RF FE. The RF FE 702 can
be connected to BB Processor 706. The BB processor 706 can be used
to process the signals transmitted and received by the RF FE 702.
The BB Processor can be connected to the IP Interface 708. The IP
interface 708 can be used to connect the interface Unit 700 to an
IP network which carries the wireless service signals to be
transferred over the DAS. The CPU 712 can be connected to the RF FE
702, the BB Processor 706, the IP Interface 708 to monitor and/or
control the operation of each of the components of the interface
unit 700.
[0053] As shown in FIG. 7, the interface unit 700 can optionally
include a GPS receiver 730 and be adapted to receive the GPS
signals and extract or recover the 1 pps timing signal. The GPS
receiver 730 can be connected to a separate antenna and be adapted
to provide the 1 pps timing signal to an external other components
of the interface unit 700 as well as components of the DAS.
[0054] As shown in FIG. 7, the interface unit 700 can include a
reference clock source 704. The reference clock source 704 can be
used to provide a reference timing signal for converting baseband
and intermediate frequency signals to or from radio frequency
signals as they are transmitted or received by the components of
the DAS. Reference clock source 704 can be a precision clock
circuit that includes a phase lock loop. Alternatively, the
reference clock source 704 can be a component that is connected to
the DAS and receives the reference clock signal distributed over
the DAS and extracts the reference timing signal for use by the
interface unit 700.
[0055] FIG. 8 shows a DAS 800 according to an alternate embodiment
of the invention. Similar to FIGS. 3, 4, 5 and 6, DAS 800 can
include one or more BTS systems providing wireless sources, a main
closet unit for distributing signals to wiring closet units, a
remote wiring closet 810 including one or more wiring closet or
combining units 814, and Source Dn 820, which can provide
interfaces to other wireless services provided over the DAS. The
system 800 can also include a reference clock source 818 which
produces a reference timing signal. The DAS 800 also includes a 1
pps timing signal. As shown in FIG. 8, the system 800 can include a
detector 832 which is adapted to receive a TDD signal and extract a
1 pps timing signal. The detector 832 can be connected to one or
more of the Source Dn units, 820 of the DAS 800, one or more of the
wiring closet or combining units 814 of the DAS 800 or one or more
of the antenna units 850 of the DAS 800. The DAS 800 can be adapted
to transfer the 1 pps timing signal to any and all components of
the DAS 800 as described herein. While FIG. 8 shows the detector
832 as a separate component, a detector 832 can be integrated with
one or more of the Source Dn units 820 of the DAS 800, one or more
of the wiring closet units 814 of the DAS 800 or one or more of the
antenna units 850. The input to the envelope detector 832 can be
any one of the Source Dn units 820 and that input will serve as the
primary source of the timing signal from which all of the other
components and TDD sources will be synchronized.
[0056] In operation of one embodiment of the invention, one or more
of the Source interface units 822, 824, 826 receives one or more
TDD signals and the detector 832 processes one or more of the TDD
signals to determine the timeslot boundaries and determine a timing
signal. In one embodiment of the invention, the timing signal is a
1 pps timing signal. In one embodiment of the invention, the
detector 832 can include an envelope detector for detecting the
timing envelope of one or more of the TDD signals.
[0057] FIG. 9 shows a DAS 900 according to an alternative
embodiment of the invention. Similar to FIGS. 3-8, DAS 900 can
include a remote wiring closet 910 including one or more wiring
closet or combining units (not shown) and other components of the
DAS. DAS 900 can include a low cost Micro, Pico or Femto Cell 920
and an antenna unit 950 that includes an analog remote radio head
960. Similar to interface 700, the Micro, Pico or Femto Cell 920
can include a baseband to intermediate frequency signal (BB-IF)
converter 902, a reference clock input PLL 904, a baseband
processor 906, an IP interface 908, a CPU 912 and a GPS receiver
(or 1 pps source) 930. The BB-IF signal converter 902 converts
baseband signal received over the IP interface 908 to intermediate
frequency signals for transmission over the DAS to the antenna
units 950 and converts the IF signals received from the antenna
units 950 to baseband signals for transmission over the DAS and
through the IP interface 908 to the supporting service network.
standard BB to RF chipset 964. The BB-IF signal converter 902 can
use the same reference clock signal to synchronize the conversion
from BB to IF and from IF to BB. The BB-IF signal converter 902 can
be connected to BB Processor 906. The BB processor 906 can be used
to process the baseband signals sent to and received from the BB-IF
signal converter 902. The BB Processor can be connected to the IP
Interface 908. The IP interface 908 can be used to connect the cell
920 to an IP network which carries the wireless service signals to
be transferred over the DAS. The CPU 912 can be connected to the
BB-IF signal converter 902, the BB Processor 906, the IP Interface
908 to monitor and/or control the operation of each of the
components of the cell 920. The cell can support multiple sections
to allow for more users or network connections as well as to
provide for multiple MIMO streams.
[0058] As shown in FIG. 9, the DAS 900 can includes include one or
more antenna units 950 that include one or more analog remote radio
heads (ARRH) 960. Each ARRH 960 can include one or more
multiplexed/de multiplexed IF-BB signal converters 962, one or more
BB-RF signal converters 964 and a input reference clock PLL
regenerator 952 The remote closet 910 can provide the same
reference clock to both reference clock PLL regenerators 952, 904.
In some embodiments of the invention, the reference clock signal
can be used without further processing, such as by a reference
clock PLL regenerator. The IF-BB signal converters 962 can be used
to convert the IF signals used to carry the individual wireless
services over the DAS 900 to the antenna unit 950 to BB signals and
the BB-RF signal converters 964 can be used to convert the BB
signals to RF signals for transmission by the antenna to the
wireless terminal devices. In addition, the BB-RF signal converters
964 can be used to convert the RF signals received from the
wireless terminal devices to BB signals and the IF-BB signal
converters 962 can be used to convert the BB signals to IF signals
used to carry the wireless signals through the DAS 900 to Source
BTS (not shown). The BB-IF signal converters 902, the IF-BB signal
converters 962 and the BB-RF signal converters 964 can include
standard chipsets that are commercially available from for example
MAXIM Integrated Products, Sunnyvale, Calif. and Analog Devices,
Inc., Norwood, Mass. In addition, the bidirectional BB-IF 902 and
the IF-BB 962 convertors can have the capability to provide
automatic gain compensation to compensate for varying cable losses
within the DAS. In addition, the BB receiver of the BB-IF and IF-BB
signal converters can provide additional capabilities including DC
offset compensation between the I,Q components of the signals and a
tunable Low Pass Filter (LPF) to improve the channel separation
from other services and provide, per channel, noise level
filtering. The ARRH 960 can use the reference timing signal
provided by the reference clock source 952 to synchronize the
conversion of the signals. The reference clock source 952 can be a
clock signal re-generator component that re-generates the reference
clock signal that is distributed through the DAS 900. The reference
clock signal can be generated by a primary reference clock signal
generator 918 connected to the main wiring closet or the remote
wiring closet 910 and distributed over the DAS 900 using one or
more of the unused frequency bands or channels carried by the DAS
900. Alternatively, the reference clock signal can be generated by
a component of the Pico or Femto Cell 920 and transferred to the
remote wiring closet 910 and distributed to the other components of
the DAS 900, including the antenna units 950, other Pico or Femto
Cells and the main wiring closet.
[0059] The DAS 900 can also include a 1 pps signal. In one
embodiment of the invention, the 1 pps signal can be generated by
GPS receiver (or an envelope detector) 930 as part of the Micro,
Pico or Femto Cell 920 and distributed over the DAS 900 to antenna
unit 950 where it is received by a component 932 of the antenna
unit 950 that regenerates, extracts or recovers the 1 pps signal
from a signal received from the DAS 900. The 1 pps signal can
distributed over the DAS 900 using one or more unused frequency
bands or channels carried by the DAS 900. The 1 pps source 930 and
932 can be a component that derives the 1 ppm signal from the 1.5
GHz GPS signal received from an antenna or over the DAS, or
alternatively, the 1 pps source 930 and 932 can be a component that
includes a synthesizer and/or a phase lock loop that regenerates,
extracts or recovers the 1 pps signal from a received signal
distributed over the DAS 900. In an alternative embodiment, the GPS
receiver (or envelope detector) 932 can be located with the antenna
unit 950 and the 1 pps signal or a signal carrying the 1 pps signal
can be sent over the DAS 900 to the other components of the DAS
including Pico or Femto Cell 920.
[0060] FIG. 10 shows a DAS 1000 according to an alternative
embodiment of the invention. Similar to FIG. 9, DAS 1000 can
include a remote wiring closet 1010 including one or more wiring
closet or combining units (not shown) and other components of the
DAS. DAS 1000 can include a low cost Pico or Femto Cell 1020 and an
antenna unit 1050 that includes an analog remote radio head 1060.
Similar to interface 920 and 700, the low cost Micro, Pico or Femto
Cell 1020 can include a baseband to radio frequency signal
converter 1002, a reference clock source 1004, a baseband processor
1006, an IP interface 1008, a CPU 1012 and a GPS receiver (or 1 pps
source) 1030. The BB-RF signal converter 1002 converts the baseband
signal received over the IP interface 1008 to RF signals for
transmission over the DAS to the antenna units 1050 and converts
the RF signals received from the antenna units 1050 to baseband
signals for transmission through the IP interface to the supporting
service network. The BB-RF signal converter 1002 can use the
reference clock signal to synchronize the conversion from BB to RF
and RF to BB. The BB-RF signal converter 1002 can be connected to
BB Processor 1006. The BB processor 1006 can be used to process the
baseband signals sent to and received from the BB-RF signal
converter 1002. The BB Processor 1006 can be connected to the IP
Interface 1008. The IP interface 1008 can be used to connect the
cell 1020 to an IP network which carries the wireless service
signals to be transferred over the DAS. The CPU 1012 can be
connected to the BB-RF signal converter 1002, the BB Processor
1006, the IP Interface 1008 to monitor and/or control the operation
of each of the components of the cell 1020. The cell can support
multiple sections to allow for more users or network connections as
well as to provide for multiple MIMO streams.
[0061] In the embodiment shown in FIG. 10, the remote closet 1010
can include one or more bidirectional multiplexed/de-multiplexed RF
to IF signal converter 1016 that can be used to convert the RF
signals received from the Cell 1020 to IF signals for transmission
to the ARRH 1060 (update the drawing) of antenna unit 1050 and to
convert IF signals received from the ARRH 1060 of the antenna unit
1050 to RF signals for transmission to the Cell 1020. In addition
the bidirectional RF to IF 1016 and the IF to RF 1062 convertors
can have the capability to provide automatic gain compensation to
compensate for varying cable losses in the DAS 1000. This
embodiment of the invention would allow the use of conventional
Micro, Pico and Femto Cells 1020 to be connected to the DAS
1000.
[0062] Similar to FIG. 9, the 1 pps signal provided by either a GPS
receiver (or an envelope detector) 1030 or a reference clock source
connected to the main closet or the remote closet 1010 can be
distributed over the DAS 1000 to the PLL 1052 in the antenna unit
1050
[0063] It is noted that in various drawing figures, more than one
cable appears to connect the components of the DAS, for example in
FIGS. 9 and 10, multiple connections are shown between the remote
closet 910, 1010 and the Cell 920, 1020 or antenna unit 950, 1050.
In accordance with the invention, only one physical cable is needed
to convey the described signals, although in alternative
embodiments of the invention more than one cable can be used. In
addition, the cables disclose herein can any medium that can be
used to transfer a signal from one location to another and that
combinations of cable types can be used. The cables can be
electrical or optical or radio frequency conducting media.
[0064] The 1 pps signal can be converted or encoded onto another
signal that is transferred through the DAS on the same cable or
medium that is used to transfer the wireless services. In
accordance with one embodiment of the invention, the 1 pps signal
can be converted or encoded onto any unused frequency that can be
transferred by the DAS. In one embodiment, the 1 pps signal is
converted to a 20-50 MHz signal for transmission through the
metallic cable media of the DAS and converted to 1.5-1.6 GHz for
transmission through the optical cable media of the DAS. In
general, the 1 pps signal can be carried on any band below 100 MHz
over metallic cable media and can be carried on any band above 1.0
GHz over optical cable media.
[0065] The reference clock signal can be converted or encoded onto
another signal that is transferred through the DAS on the same
cable or medium that is used to transfer the wireless services. In
accordance with one embodiment of the invention, the reference
clock signal can be, for example, an Oven Controlled Crystal
Oscillator (OCXO) at 10-20 Mhz signal that is converted or encoded
onto any unused frequency that can be transferred by the DAS. In
one embodiment, the reference clock signal is converted to a
1.5-2.0 Ghz signal for transmission through the DAS.
[0066] Other embodiments are within the scope and spirit of the
invention. For example, due to the nature of software, functions
described above can be implemented using software, hardware,
firmware, hardwiring, or combinations of any of these. Features
implementing functions may also be physically located at various
positions, including being distributed such that portions of
functions are implemented at different physical locations.
[0067] Further, while the description above refers to the
invention, the description may include more than one invention.
* * * * *