U.S. patent number RE48,499 [Application Number 15/423,724] was granted by the patent office on 2021-03-30 for timing adjustments for small cell distributed antenna systems.
This patent grant is currently assigned to CommScope Technologies LLC. The grantee listed for this patent is CommScope Technologies LLC. Invention is credited to Larry G. Fischer, Kenneth Anderson Stewart, Lance K. Uyehara.
United States Patent |
RE48,499 |
Fischer , et al. |
March 30, 2021 |
Timing adjustments for small cell distributed antenna systems
Abstract
A distributed antenna system includes a host unit
communicatively coupled to a first service provider interface which
receives a first signal from the first service provider interface;
and a first remote antenna unit communicatively coupled to the host
unit, the first remote antenna unit having a first antenna. A base
station to which the distributed antenna system is communicatively
coupled is configured with a subscriber access timing window having
a minimum allowed delay and a maximum allowed delay. The
distributed antenna system is configured so that a first total
delay between the host unit and the first remote antenna unit is
equal to or greater than the minimum allowed delay. The first
antenna of the first remote antenna unit is configured to
communicate the first signal to a first subscriber unit.
Inventors: |
Fischer; Larry G. (Waseca,
MN), Stewart; Kenneth Anderson (Sunnyvale, CA), Uyehara;
Lance K. (San Jose, CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
CommScope Technologies LLC |
Hickory |
NC |
US |
|
|
Assignee: |
CommScope Technologies LLC
(Hickory, NC)
|
Family
ID: |
48946012 |
Appl.
No.: |
15/423,724 |
Filed: |
February 3, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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61598668 |
Feb 14, 2012 |
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Reissue of: |
13765848 |
Feb 13, 2013 |
8948816 |
Feb 3, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W
88/08 (20130101); H04W 24/02 (20130101); H04W
88/085 (20130101) |
Current International
Class: |
H04B
1/00 (20060101); H04B 1/38 (20150101); H04W
88/08 (20090101); H04W 24/02 (20090101) |
Field of
Search: |
;455/561,435.1,456.5 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1553791 |
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Jul 2005 |
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EP |
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1020080015462 |
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Feb 2008 |
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KR |
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1020110104957 |
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Sep 2011 |
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KR |
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2006135697 |
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Dec 2006 |
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WO |
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2010083115 |
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Jul 2010 |
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WO |
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Other References
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13/765,848", dated Aug. 28, 2014, pp. 1-12, Published in: WO. cited
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13/765,848", dated Jun. 2, 2013, pp. 1-16, Published in: WO. cited
by applicant .
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Action for CN Application No. 201380019886.8 dated Jun. 8, 2015",
"Foreign Counterpart to U.S. Appl. No. 13/765,848", filed Jun. 8,
2015, pp. 1-15, Published in: CN. cited by applicant .
State Intellectual Property Office, P.R. China, "Second Office
Action for CN Application No. 201380019886.8 dated Dec. 1, 2015",
"Foreign Counterpart to U.S. Appl. No. 13/765,848", filed Dec. 1,
2015, pp. 1-4, Published in: CN. cited by applicant .
State Intellectual Property Office, P.R. China, "Third Office
Action for CN Application No. 201380019886.8 dated Mar. 11, 2016",
"Foreign Counterpart to U.S. Appl. No. 13/765,848", filed Mar. 11,
2016, pp. 1-4, Published in: CN. cited by applicant .
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Submissions / Oral Proceedings from EP Application No. 13749159.3
dated Mar. 27, 2019", from Foreign Counterpart to U.S. Appl. No.
13/765,848, pp. 1-10, Published: EP. cited by applicant .
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No. 13/765,848, dated Dec. 9, 2019, pp. 1-9, Published: EP. cited
by applicant.
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Primary Examiner: Nguyen; Minh Dieu
Attorney, Agent or Firm: Fogg & Powers LLC
Claims
What is claimed is:
1. A distributed antenna system comprising: a host unit
communicatively coupled to a .[.first service provider interface
which receives.]. .Iadd.base station external to the distributed
antenna system, the host unit configured to receive .Iaddend.a
first signal from the .[.first service provider interface.].
.Iadd.base station.Iaddend.; a first remote antenna unit
communicatively coupled to the host unit, the first remote antenna
unit having a first antenna; wherein .[.a.]. .Iadd.the
.Iaddend.base station to which the distributed antenna system is
communicatively coupled is configured with a subscriber access
timing window .[.having.]. .Iadd.including a time after .Iaddend.a
minimum .[.allowed.]. delay and .Iadd.before .Iaddend.a maximum
.[.allowed.]. delay.Iadd., wherein the base station considers a
subscriber to be within range of the base station when an
acknowledgement message is received from the subscriber within the
subscriber access timing window.Iaddend.; wherein the distributed
antenna system is configured so that a first total delay between
the host unit and the first remote antenna unit is equal to or
greater than the minimum .[.allowed.]. delay; and wherein the first
antenna of the first remote antenna unit is configured to
communicate the first signal to a first subscriber unit, wherein a
coverage area of communication from the first antenna of the first
remote antenna unit .[.is proportional to.]. .Iadd.is a function of
.Iaddend.the first total delay.
2. The distributed antenna system of claim 1, wherein the first
total delay comprises at least one of: a first inherent delay in
the distributed antenna system between the host unit and the first
remote antenna unit; a first propagation delay between the host
unit and the first remote antenna unit; and a first additional
configurable delay.
3. The distributed antenna system of claim 1, wherein the first
total delay comprises a first configurable delay.
4. The distributed antenna system of claim 1, wherein .[.a.].
.Iadd.the .Iaddend.coverage area of communication from the first
antenna of the first remote antenna unit becomes smaller as the
first total delay increases.
5. The distributed antenna system of claim 1, wherein the first
remote antenna unit is communicatively coupled to the host unit via
a physical medium.
6. The distributed antenna system of claim 5, wherein the physical
medium is at least one of a fiber optical cable, a coaxial cable,
or twisted pair.
7. The distributed antenna system of claim 1, wherein the first
remote antenna unit is communicatively coupled to the host unit via
a wireless medium.
8. The distributed antenna system of claim 1, wherein the .[.first
service provider interface.]. .Iadd.base station .Iaddend.is
configured to output, and receive as input, respective digital
baseband data; and wherein the first signal is a digital baseband
data signal.
9. The distributed antenna system of claim 8, wherein the
.Iadd.respective .Iaddend.digital baseband data comprises in-phase
digital baseband data and quadrature digital baseband data; and
wherein the first signal comprises .[.in phase.]. .Iadd.in-phase
.Iaddend.digital baseband data and quadrature digital baseband
data.
10. The distributed antenna system of claim 8, wherein the host
unit further comprises a baseband interface that receives from, and
outputs to, the .[.first service provider interface.]. .Iadd.base
station .Iaddend.respective digital baseband data.
11. The distributed antenna system of claim 10, wherein the
baseband interface is configured to perform a protocol conversion
between a first baseband protocol used by the .[.first service
provider interface.]. .Iadd.base station .Iaddend.and a second
baseband protocol used by the first remote antenna unit.
12. The distributed antenna system of claim 10, wherein the
baseband interface is configured to multiplex digital baseband
data.
13. The distributed antenna system of claim 1, wherein the .[.first
service provider interface.]. .Iadd.base station .Iaddend.is
configured to output, and receive as input, radio frequency
signals; and wherein the first signal is a radio frequency
signal.
14. The distributed antenna system of claim 1, wherein the
.[.service provider interface.]. .Iadd.base station
.Iaddend.interacts with a carrier network via an Internet protocol
(IP) network.
15. The distributed antenna system of claim 1, wherein the first
remote antenna unit is communicatively coupled to the host unit via
at least one intermediary device.
16. The distributed antenna system of claim 15, wherein the
.Iadd.at least one .Iaddend.intermediary device comprises an
expansion hub.
17. The distributed antenna system of claim 15, wherein the
distributed antenna system is a hybrid distributed antenna system;
wherein the .Iadd.at least one .Iaddend.intermediary device
comprises a remote server unit that interfaces between a digital
portion of the distributed antenna system and an analog portion of
the distributed antenna system; wherein the digital portion of the
distributed antenna system includes digital communication between
the host unit and the remote server unit; wherein the remote server
unit converts between digital and analog signals; and wherein the
analog portion of the distributed antenna system includes analog
communication between the remote server unit and the first remote
antenna unit.
18. The distributed antenna system of claim 1, wherein the
distributed antenna system is configured to distribute multiple
services.
19. The distributed antenna system of claim 1, wherein the
distributed antenna system is coupled to multiple wireless service
providers' networks.
20. The distributed antenna system of claim 1, wherein the
distributed antenna system is configured for use in at least one
of: in-building applications, outdoor applications, enterprise
applications, public safety applications, and military
applications.
21. The distributed antenna system of claim 1, further comprising
groups of .[.the.]. remote antenna units that are configurable for
local joint beamforming and/or joint transmission groups of
cells.
22. The distributed antenna system of claim 1, further comprising:
a second remote antenna unit communicatively coupled to the host
unit, the second remote antenna unit having a second antenna;
wherein the distributed antenna system is configured so that a
second total delay between the host unit and the second remote
antenna unit is equal to or greater than the minimum .[.allowed.].
delay; and wherein the second antenna of the second remote antenna
unit is configured to communicate .[.the first.]. .Iadd.a second
.Iaddend.signal to a second subscriber unit.
23. The distributed antenna system of claim 22, wherein the second
total delay comprises at least one of: a second inherent delay in
the distributed antenna system between the host unit and the second
remote antenna unit; a second propagation delay between the host
unit and the second remote antenna unit; and a second additional
configurable delay.
24. The distributed antenna system of claim 22, wherein a
.Iadd.second .Iaddend.coverage area of communication from the
second antenna of the second remote antenna unit is proportional to
the second total delay.
25. The distributed antenna system of claim 22, wherein the second
remote antenna unit is communicatively coupled to the host unit via
a physical medium.
26. The distributed antenna system of claim 25, wherein the
physical medium is at least one of a fiber optic cable, a coaxial
cable, or twisted pair.
27. The distributed antenna system of claim 1, further comprising:
wherein the host unit is further communicatively coupled to a
second .[.service provider interface.]. .Iadd.base station
.Iaddend.which receives a second signal from the second .[.service
provider interface.]. .Iadd.base station.Iaddend.; and wherein at
least one antenna of .[.the first.]. .Iadd.a second .Iaddend.remote
antenna unit is configured to communicate the second signal to a
second subscriber unit.
28. The distributed antenna system of claim 27, wherein the second
.[.service provider interface.]. .Iadd.base station .Iaddend.is
configured to output, and receive as input, respective digital
baseband data; and wherein the second signal is a digital baseband
data signal.
29. The distributed antenna system of claim 27, wherein the second
.[.service provider interface.]. .Iadd.base station .Iaddend.is
configured to output, and receive as input, radio frequency
signals; and wherein the second signal is a radio frequency
signal.
30. The distributed antenna system of claim 27, wherein the second
remote antenna unit is communicatively coupled to the host unit via
at least one intermediary device.
31. The distributed antenna system of claim 1, further comprising:
wherein the host unit is further communicatively coupled to a
second .[.service provider interface.]. .Iadd.base station
.Iaddend.which receives a second signal from the .[.service
provider interface.]. .Iadd.second base station.Iaddend.; a second
remote antenna unit communicatively coupled to the host unit, the
second remote antenna unit having a second antenna; wherein the
distributed antenna system is configured so that a second total
delay between the host unit and the second remote antenna unit is
equal to or greater than the minimum .[.allowed.]. delay; and
wherein the second antenna of the second remote antenna unit is
configured to communicate the second signal to a second subscriber
unit.
32. The distributed antenna system of claim 31, wherein the second
total delay comprises at least one of: a second inherent delay in
the distributed antenna system between the host unit and the second
remote antenna unit; a second propagation delay between the host
unit and the second remote antenna unit; and a second additional
configurable delay.
33. The distributed antenna system of claim 31, wherein the second
remote antenna unit is communicatively coupled to the host unit via
a physical medium.
34. The distributed antenna system of claim 31, wherein the second
.[.service provider interface.]. .Iadd.base station .Iaddend.is
configured to output, and receive as input, respective digital
baseband data; and wherein the second signal is a digital baseband
data signal.
35. The distributed antenna system of claim 31 wherein the second
.[.service provider interface.]. .Iadd.base station .Iaddend.is
configured to output, and receive as input, radio frequency
signals; and wherein the second signal is a radio frequency
signal.
36. The distributed antenna system of claim 31, wherein the second
remote antenna unit is communicatively coupled to the host unit via
at least one intermediary device.
37. The distributed antenna system of claim 36, wherein the
distributed antenna system is a hybrid distributed antenna system;
wherein the .Iadd.at least one .Iaddend.intermediary device
comprises a remote server unit that interfaces between a digital
portion of the distributed antenna system and an analog portion of
the distributed antenna system; wherein the digital portion of the
distributed antenna system includes digital communication between
the host unit and the .[.second.]. remote server unit; wherein the
remote server unit converts between digital and analog signals; and
wherein the analog portion of the distributed antenna system
includes analog communication between the remote server unit and
the second remote antenna unit.
38. A method comprising: configuring a distributed antenna system
to have a first additional delay .Iadd.of signals communicated
within the distributed antenna system between a host unit and a
first remote antenna unit .Iaddend.in addition to a first inherent
delay of the .Iadd.signals communicated within the
.Iaddend.distributed antenna system between .[.a.]. .Iadd.the
.Iaddend.host unit and .[.a.]. .Iadd.the .Iaddend.first remote
antenna unit; wherein the distributed antenna system is
communicatively coupled to a base station .Iadd.external to the
distributed antenna system and configured to receive a first signal
from the base station and to propagate a second signal based on the
first signal through the distributed antenna system, wherein the
base station is .Iaddend.configured with a subscriber access timing
window .[.having.]. .Iadd.including a time after .Iaddend.a minimum
.[.allowed.]. delay and .Iadd.before .Iaddend.a maximum
.[.allowed.]. delay.Iadd., wherein the base station considers a
subscriber to be within range of the base station when an
acknowledgement message is received from the subscriber within the
subscriber access timing window.Iaddend.; wherein a first total
delay of the first additional delay and the first inherent delay of
.Iadd.the second signal within .Iaddend.the distributed antenna
system is equal to or greater than the minimum .[.allowed.]. delay;
and wherein a coverage area of communication .Iadd.of a third
signal .Iaddend.from a first antenna of the first remote antenna
unit .[.is proportional to.]. .Iadd.is a function of .Iaddend.the
first total delay.Iadd., wherein the third signal is based on the
second signal.Iaddend..
39. The method of claim 38, wherein the first inherent delay
comprises at least one of a propagation delay between the host unit
and the first remote antenna unit.
40. The method of claim 38, further comprising transporting signals
from the base station through the distributed antenna system via a
physical medium.
41. The method of claim 38, further comprising communicating
digital baseband data between .[.a service provider interface of.].
the base station and the host unit of the distributed antenna
system.
42. The method of claim 38, further comprising communicating radio
frequency signals between .[.a service provider interface of.]. the
base station and the host unit of the distributed antenna
system.
43. The method of claim 38, further comprising: configuring .[.a.].
.Iadd.the .Iaddend.distributed antenna system to have a second
additional delay in addition to a second inherent delay of the
distributed antenna system between the host unit and a second
remote antenna unit; and wherein a second total delay of the second
additional delay and the second inherent delay of the distributed
antenna system is equal to or greater than the minimum
.[.allowed.]. delay.
44. A distributed antenna system comprising: a host unit
communicatively coupled to a .[.first service provider interface
which receives.]. .Iadd.base station external to the distributed
antenna system, the host unit configured to receive .Iaddend.a
first signal from the .[.first service provider interface.].
.Iadd.base station.Iaddend.; a first remote antenna unit
communicatively coupled to the host unit; wherein .[.a.]. .Iadd.the
.Iaddend.base station to which the distributed antenna system is
communicatively coupled is configured with a subscriber access
timing window .[.having.]. .Iadd.including a time after .Iaddend.a
minimum .[.allowed.]. delay and .Iadd.before .Iaddend.a maximum
.[.allowed.]. delay.Iadd., wherein the base station considers a
subscriber to be within range of the base station when an
acknowledgement message is received from the subscriber within the
subscriber access timing window.Iaddend.; wherein the distributed
antenna system is configured .Iadd.to propagate a second signal
based on the first signal between the host unit and the first
remote antenna unit .Iaddend.so that a first total delay .Iadd.of
the second signal propagated .Iaddend.between the host unit and the
first remote antenna unit is equal to or greater than the minimum
.[.allowed.]. delay; and wherein a coverage area of communication
.Iadd.of a third signal .Iaddend.from a first antenna of the first
remote antenna unit .[.is proportional to.]. .Iadd.is a function of
.Iaddend.the first total delay.Iadd., wherein the third signal
based on the second signal.Iaddend..
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
.Iadd.This Reissue Application is a reissue of application Ser. No.
13/765,848, filed Feb. 13, 2013, which issued as U.S. Pat. No.
8,948,816. .Iaddend.This application claims the benefit of U.S.
Provisional Patent Application Ser. No. 61/598,668, filed on Feb.
14, 2012, which is hereby incorporated herein by reference.
BACKGROUND
This disclosure relates to distributed antenna systems, repeaters,
distributed base station systems, and the like.
SUMMARY
A distributed antenna system includes a host unit communicatively
coupled to a first service provider interface which receives a
first signal from the first service provider interface; and a first
remote antenna unit communicatively coupled to the host unit, the
first remote antenna unit having a first antenna. A base station to
which the distributed antenna system is communicatively coupled is
configured with a subscriber access timing window having a minimum
allowed delay and a maximum allowed delay. The distributed antenna
system is configured so that a first total delay between the host
unit and the first remote antenna unit is equal to or greater than
the minimum allowed delay. The first antenna of the first remote
antenna unit is configured to communicate the first signal to a
first subscriber unit.
DRAWINGS
Understanding that the drawings depict only exemplary embodiments
and are not therefore to be considered limiting in scope, the
exemplary embodiments will be described with additional specificity
and detail through the use of the accompanying drawings, in
which:
FIG. 1A-1B are block diagrams depicting exemplary embodiments of
systems including small cell base stations according to the present
disclosure; and
FIGS. 2A-2C are block diagrams depicting exemplary embodiments of
systems including small cell base stations and distributed antenna
systems according to the present disclosure.
In accordance with common practice, the various described features
are not drawn to scale but are drawn to emphasize specific features
relevant to the exemplary embodiments.
DETAILED DESCRIPTION
In the following detailed description, reference is made to the
accompanying drawings that form a part hereof, and in which is
shown by way of illustration specific illustrative embodiments.
However, it is to be understood that other embodiments may be
utilized and that logical, mechanical, and electrical changes may
be made. Furthermore, the method presented in the drawing figures
and the specification is not to be construed as limiting the order
in which the individual steps may be performed. The following
detailed description is, therefore, not to be taken in a limiting
sense.
FIG. 1A shows an exemplary embodiment of a system including a small
cell base station 102 having an antenna 104 and a circular coverage
area 106. In exemplary embodiments, the small cell base station 102
is designed to cover a small radius directly surrounding the small
cell base station 102 location. This keeps the small cell from
interfering with other neighboring cells and trying to capture
subscriber units who are further away from the cell while still
having strong radio frequency ("RF") signal within the cell. The
range of coverage of the small cell is determined by the time delay
between when the RF signal leaves the small cell base station 102,
is received at the subscriber, and a response is received back at
the small cell base station 102. In exemplary embodiments, the
calculation of range of coverage of the small cell base station 102
(the area covered by the small cell) is not affected by the RF
signal strength of the subscriber at the small cell base station
102 or the RF signal strength at the subscriber. In exemplary
embodiments, the small cell base station 102 and/or the subscriber
units ensure that it provides sufficient power such that the RF
signal strength of the subscriber at the small cell base station
102 and the RF signal strength at the subscriber. In exemplary
embodiments, the output power level at the small cell base station
102 and/or the subscriber units is adjusted based on the range of
coverage of the small cell base station 102 (the area covered by
the small cell). In some implementations, the output power level at
the small cell base station 102 and/or the subscriber units are
adjusted proportional to any adjustment of the delay. In
implementations of such an embodiment, the distance D1 from the
center of the circular coverage area 106 to the outer limit of the
circular coverage area 106 (the radius of the circular coverage
area 106) provided by the small cell base station 102 is less than
about 200 meters. In implementations of such an embodiment, the
distance D1 relates to a subscriber access timing window during
which the small cell base station 102 accepts subscriber
responses.
In implementations of such an embodiment, the small cell base
station 102 only identifies subscribers that respond with an
acknowledgement to a request message from the small cell base
station 102 within the subscriber access timing window. In such
implementations, the subscriber access timing window has a minimum
allowable delay and a maximum allowable delay. In exemplary
implementations, the delays are on the order of microseconds. If a
first exemplary subscriber's acknowledgement message is received
back at the small cell base station 102 within the subscriber
access timing window (both after the minimum allowable delay and
before the maximum allowable delay), the first exemplary subscriber
is considered to be effectively within range of the small cell base
station 102 and that subscriber's traffic is routed through the
small cell base station 102. If a second exemplary subscriber's
acknowledgement message is not received back at the small cell base
station 102 before the subscriber access timing window ends (after
the maximum allowable delay), the second exemplary subscriber is
considered to be effectively too far away and out of range of the
small cell base station 102 and that subscriber's traffic is
ignored by the small cell base station 102. If a third exemplary
subscriber's acknowledgement message is received back at the small
cell base station 102 before the subscriber access timing window
starts (before the minimum allowable delay), the third exemplary
subscriber is considered to be effectively too close and is out of
range of the small cell base station 102 and that subscriber's
traffic is ignored by the small cell base station 102.
In implementations of such an embodiment, the small cell base
station 102 limits the turn around time between the subscriber unit
and the base station to limit the radius of coverage. In these
implementations, the turn around time is a limit on the amount of
time allowed between sending out a request and receiving a
response. In exemplary implementations, the turn around times are
on the order of milliseconds. In implementations of such an
embodiment, the distance D1 is being limited to reduce multipath,
bouncing, and reflection of signals and the actual RF signal
strength is not limiting the distance D1. Thus, responses from
subscribers within the circular coverage area 106 would fall within
the subscriber access timing window of accepted subscriber
responses. In implementations of such an embodiment, the subscriber
access timing window is adjustable, causing the distance D1 to
increase or decrease as the subscriber access timing window
increases or decreases.
In implementations of such an embodiment, the use of subscriber
access timing windows aid in minimizing the processing overhead at
the small cell base station 102. In such implementations, because
the small cell base station 102 ignores traffic from subscribers
that fall outside of the subscriber access timing window, there is
less traffic to process.
In implementations of such an embodiment implementing CDMA or
WCDMA, these signals are in the form of code sequences. In such
implementations, the subscriber access timing windows are WCDMA
subscriber access timing windows. In implementations utilizing
WCDMA, rake receivers may also be implemented to capture multiple
copies of the signal originating from the transmitter due to
multipath, signal blocking, reflection, diffraction, refraction,
and the distance from the transmitter. In such implementations, in
addition to the subscriber access timing window described above,
the rake receivers have smaller windows of time within a frame
during which they capture and resolve multiple time-shifted copies
of signals from subscribers into a single signal. In such
implementations, a range of timeslots within the frame are
processed by the rake receiver to resolve the signal. In some
implementations using WCDMA, each rake receivers have multiple
sub-radios (called fingers) that collect the energy at different
timeslots surrounding the expected timeslot for a particular
subscriber's signal (such as a code) to resolve the plurality of
time delayed and/or time advanced signals into a single signal for
the subscriber. In implementations using WCDMA, small cell base
station 102 has fewer sub-radios (fingers) in their rake receivers
due to size and cost considerations. In such implementations, a
small cell base station 102 may only have a few sub-radios
(fingers) in its rake receiver.
In implementations of such an embodiment, the subscriber access
timing window is adjusted so that the area of coverage that
radiates from a small cell base station 102 antenna forms a ring
shaped coverage area (also described as a "donut" shaped area of
coverage) having a band of coverage a certain distance away from
the radiating antenna and a circular area of no coverage within the
ring shaped coverage area (also described as a "donut hole" shaped
area of no coverage within the "donut" shaped area of coverage). In
implementations of such an embodiment, the subscriber access timing
window is adjusted by adding an additional delay to any intrinsic
delay at the small cell base station 102. In such implementations,
the acceptable range of the subscriber access timing window is
pushed out further in time (and accordingly in space) to create the
circular area of no coverage within the ring shaped coverage
area.
FIG. 1B shows an exemplary embodiment of a system including a small
cell base station 102 having an antenna 104 and a ring shaped
coverage area 106 with a circular area of no coverage within the
ring shaped coverage area 106. In implementations of such an
embodiment, the ring shaped coverage area 106 has a thickness of a
distance D1 of less than about 200 meters. In implementations of
such an embodiment, the circular area of no coverage 108 within the
ring shaped coverage area 106 has a distance D3 from its center to
the beginning of the ring shaped coverage area 106 that is less
than about 200 meters. In implementations of such an embodiment,
the ring shaped coverage area 106 with the circular area of no
coverage within the ring shaped coverage area 106 is created from
the example in FIG. 1 when additional delay is added at the small
cell base station 102, thereby causing the subscriber access timing
window for accepted subscriber responses to be pushed out. In
implementations of such embodiments, this additional delay relates
to the distance D3. As this additional delay increases, the
distance D3 increases. As this additional delay decreases, the
distance D3 decreases. In implementations of such embodiments, the
thickness of the ring shaped coverage area 106 can be adjusted
based on the subscriber access timing window duration and the size
of the circular area of no coverage within the ring shaped coverage
area 106 can be adjusted based on the additional time delay added
to the small cell base station 102.
In implementations of such embodiments, mobile units would not be
able to connect to the base station 102 if they are within the
circular area of no coverage 108 because they would respond too
quickly to fall within the subscriber access timing window.
Similarly, mobile units would not be able to connect to the base
station 102 if they are further out than the ring shaped coverage
area 106 because they would respond too slowly to fall within the
subscriber access timing window. In contrast, mobile units would be
able to connect to the base station 102 if they are within the ring
shaped coverage area 106 because they would respond within the
subscriber access timing window.
In such implementations, a specific amount of delay could be added
to the subscriber access timing window. For example, an original
subscriber access timing window might have a range of between 0 and
10 microseconds and then additional delay of 30 microseconds is
added to the range, causing it to be between 30 and 40
microseconds. Subscribers within the ring shaped coverage area
(between 30 and 40 microsecond response time in this example) would
be considered "in range" subscribers and those within the circular
area of no coverage within the ring shaped coverage area (between
0-30 microseconds response time in this example) or those out past
the ring shaped coverage area (greater than 40 microseconds
response time in this example) would be considered "out of range"
subscribers.
In exemplary embodiments, the signal from the small cell base
station 102 can be fed through a distributed antenna system (DAS)
200 and the ring shaped coverage area will be moved in to a certain
area, depending on the inherent delay of the distributed antenna
system 200 and the desired size of the planned coverage area at a
remote antenna unit (RAU) 204 of the distributed antenna system
200. In implementations of such an embodiment, the distributed
antenna system 200 has an inherent delay time required for signals
to propagate through the distributed antenna system 200. In
implementations of such an embodiment, the inherent delay time is
equal for all legs of the distributed antenna system 200. In other
implementations of such an embodiment, the inherent delay time is
different for legs of the distributed antenna system 200 based on
the length of each distributed antenna system 200 leg and the
various processing, conversions, etc. that occur in the distributed
antenna system 200.
In implementations of the digital distributed antenna system 200,
the inherent delay of the distributed antenna system 200 uses up
the circular area with no coverage within the ring shaped coverage
area and causes it to disappear, thereby constricting the ring
shaped coverage area down to a circular based coverage area. In
implementations of such an embodiment, each of the remote antenna
units within the distributed antenna system 200 radiate circular
coverage areas. In implementations of such an embodiment, the small
base station itself is not used to radiate signals because of its
ring shaped coverage area, but instead the remote antenna units of
the distributed antenna system 200 are used to cover a particular
area.
FIG. 2A shows an exemplary embodiment of a system including a small
cell base station 102 coupled with a distributed antenna system
(DAS) 200 having at least one host unit 202 and at least one remote
antenna unit (RAU) 204 coupled to the host unit 202 by a
communication link 206. In exemplary implementations, the at least
one host unit 202 includes a plurality of service provider
interfaces (such as base station transceivers), a switch, and a
scheduler. Each service provider interface is configured to output
a respective downstream frequency and a respective upstream
frequency. The switch is configured to route each of the plurality
of downstream frequencies to at least one remote antenna unit 202
and to route each of a plurality of upstream frequencies to
respective subset of the service provider interfaces. In exemplary
embodiments, the scheduler is co-located with the service provider
interfaces. In exemplary embodiments, the host unit 202 further
comprises a baseband interface that receives from, and outputs to,
the service provider interfaces respective digital baseband data.
The baseband interface can optionally be configured to perform
protocol conversion between a first baseband protocol used by the
base station transceiver and a second baseband protocol used by the
plurality of remote antenna units. The baseband interface can
optionally be configured to multiplex digital baseband data. In
exemplary embodiments, the service provider interfaces comprise a
plurality of home node B (HNB) base station transceivers and/or a
plurality of enhanced home node B (EHNB) base station transceivers.
In one implementation of such an embodiment, each of the plurality
of HNB base station transceivers implements at least one
third-generation (3G) protocol and/or each of the plurality of EHNB
base station transceivers implements at least one fourth-generation
(4G) protocol.
In other exemplary implementations, the at least one host unit 202
includes a plurality of reconfigurable baseband processors, a
switch, and a system controller. In exemplary embodiments, each of
the reconfigurable baseband processors is configured to output a
respective downstream frequency and a respective upstream
frequency. The switch is configured to route each of a plurality of
downstream frequencies to a respective subset of the remote antenna
units and to route each of a plurality upstream frequencies to a
respective subset of the reconfigurable baseband processors. The
system controller implements a scheduler to control the operation
of the switch and the base station transceivers. The system
controller and the associated scheduler are co-located with the
reconfigurable baseband processors. In one implementation, the host
unit 202 further comprises a bus that communicatively couples the
reconfigurable baseband processors, the system controller, and the
switch to one another. The bus can optionally comprise a Peripheral
Component Interconnect Express (PCIe) bus. In one implementation,
the host unit 202 further comprises a plurality of Small
Form-Factor Pluggable (SFP) lasers. In one implementation, the host
unit 202 further comprises a plurality of Small Form-Factor
Pluggable (SFP) laser modules that are configured to
communicatively couple the host unit 202 to the plurality of remote
antenna units 204. In one implementation, the reconfigurable
baseband processors are configured to output, and receive as input,
respective digital baseband data. The digital baseband data can
optionally comprise in-phase digital baseband data and quadrature
digital baseband data. In one implementation, the reconfigurable
baseband processors can be configured to implement at least one of
a home node B (HNB) base station transceiver and an enhanced home
node B (EHNB) base station transceiver. In one implementation of
such an embodiment, the reconfigurable baseband processors can be
configured to implement at least one third-generation (3G) protocol
and/or at least one fourth-generation (4G) protocol.
In one implementation, the scheduler is implemented as a
low-latency joint scheduler (LUS). In one implementation, the
switch is implemented as a space-frequency switch (SFS). In one
implementation, the host unit 202 is configured to intercept UE
reports of cell measurements. In one implementation, the
distributed antenna system 200 further comprises a measurement
receiver in each remote antenna unit 204 to measure path loss to
neighbor remote antenna units 204. In one implementation, the
distributed antenna system 200 is configured to monitor traffic and
measurement data passing through the system in order to estimate
traffic load per remote antenna unit 204 and/or traffic load per
user device. The traffic load estimates can optionally be used by
the scheduler. In one implementation, the scheduler implements at
least one of semi-static scheduling and dynamic scheduling. In one
implementation, the system is configured for use with a MIMO
protocol. In one implementation, each of the service provider
interfaces (base station transceivers) interacts with a carrier
network via an Internet protocol (IP) network. Each of the service
provider interfaces can optionally be coupled to an access gateway
that controls access to the carrier network.
In one implementation, at least some of the remote antenna units
204 are communicatively coupled to the host unit 202 via at least
one intermediary device. The intermediary device can optionally
comprise an expansion hub. In one implementation, the distributed
antenna system 200 is configured to distribute multiple services.
In one implementation, the distributed antenna system is coupled to
multiple wireless service providers' networks. In one
implementation, the distributed antenna system is configured for
use in at least one of: in-building applications, outdoor
applications, enterprise applications, public safety applications,
and military applications. In one implementation, groups of the
remote antenna units 204 are configurable for local joint
beamforming and/or joint transmission groups of cells. In exemplary
embodiments, a plurality of low power remote antenna units 204 with
a higher density enable lower cost individual components.
Accordingly, the low cost individual remote antenna units 204 can
be used in a building block approach to create a network with
coverage tailored to a particular application or environment. In
exemplary embodiments, the plurality of remote antenna units 204
enable greater reliability.
While the small cell base station 102 and the host unit 202 are
described as being separate components above, in exemplary
embodiments, the two are combined into a single system or
apparatus. In one implementation, the distributed antenna system
200 is configured for use with licensed radio frequency spectrum
(including, but not limited to, cellular licensed radio frequency
spectrum). In one implementation, the distributed antenna system
200 is configured for use with unlicensed radio frequency spectrum
(including, but not limited to, IEEE 802.11 radio frequency
spectrum).
The at least one remote antenna unit 204 includes an antenna 208
and a circular coverage area 210. In implementations of such an
embodiment, the distance D5 from the center of the circular
coverage area 210 to the outer limit of the circular coverage area
210 (the radius of the circular coverage area 210) provided by the
remote antenna unit 204 is less than about 200 meters. In
implementations of such an embodiment, the distance D5 relates to
the subscriber access timing window during which the small cell
base station 102 accepts subscriber response described with
reference to FIGS. 1A-1B above. In implementations of such an
embodiment, the small cell base station 102 does not transmit or
receive RF signals from an antenna itself and instead relies upon
the distributed antenna system 200 to do the transmission and
reception because the small cell base station 102 would have a ring
shaped coverage area 108 as shown in FIG. 1B which is not
particularly useful because signals transmitted to the ring shaped
coverage area 108 have to travel a relatively far distance and will
be attenuated by the propagation distance.
In implementations of the digital distributed antenna system 200,
the circular coverage area 210 is created from the ring shaped
coverage area 106 of FIG. 2A when the signals are passed through
the distributed antenna system 200 instead of directly being
radiated from the small cell base station 102 and the additional
delay added to the signals offsets the additional delay added to
the subscriber access timing window in the small cell base station
102. Specifically, a distributed antenna system 200 includes
inherent delay in its various legs from any conversion, filtering,
propagation, and reconstruction time. In such implementations, the
delay caused by converters, analog filters, and the rest of the
circuitry surrounding an RF signal could take around 6 microsecond
in each direction, for a total of 12 microseconds round trip. In
such implementations, the delay from fiber causes it to go slower
as well, such that light propagation in fiber optic cables is only
about 68% the speed of light propagation in free space. In such
implementations, the fiber delay from light propagation through the
fiber can be on the order of a few microseconds per mile.
In implementations of the digital distributed antenna system 200,
the total delay through the distributed antenna system 200 caused
by the inherent delay of the distributed antenna system 200 and the
additional delay is subtracted from the subscriber access timing
window. In the exemplary implementation described above with a
subscriber access timing window between 30 and 40 microseconds
where the total delay through the distributed antenna system 200 is
30 microseconds, the subscriber access timing window after being
passed through the distributed antenna system 200 is effectively 0
to 10 microseconds.
In implementations of the digital distributed antenna system 200,
the inherent delay may include digitization, signal propagation
through an optical fiber or other medium, and reconstruction of the
RF signals from digitized signals. In implementations of analog
distributed antenna system 200, the inherent delay may include
conversion to an intermediate frequency, signal propagation through
coaxial cable, optical fiber, twisted pair, free space media (or
other wireless media), or other media, and reconstruction of the RF
signals from the intermediate frequency signals. In implementations
of hybrid distributed antenna system 200, the inherent delay may
include digitization, signal propagation through an optical fiber
or other medium, conversion of digital signals to intermediate
frequency analog signals, signal propagation through coaxial cable,
optical fiber, free space medium, twisted pair, or other media, and
reconstruction of the RF signals from the intermediate frequency
signals.
In implementations of the digital distributed antenna system 200,
the distance D5 from the center of the circular coverage area 106
to the outer limit of the circular coverage area 106 (the radius of
the circular coverage area 106) provided by the small cell base
station 102 is less than about 200 meters. In implementations of
such an embodiment, the distance D5 relates to a subscriber access
timing window during which the small cell base station 102 accepts
subscriber responses. Thus, responses from subscribers within the
circular coverage area 106 would fall within the subscriber access
timing window of accepted "in range" subscriber responses.
In implementations of the digital distributed antenna system 200,
the small cell base station 102 has a subscriber access timing
window between 30 and 40 microseconds so that it will process
acknowledgement messages from subscribers that fall within the
30-40 microsecond subscriber access timing window. Acknowledgement
message from subscribers that fall outside of the 30-40 microsecond
subscriber access timing window are consider out of range and are
ignored. The inherent delay in a leg of the distributed antenna
system 200 takes up 30 microseconds, effectively turning the 30-40
microsecond subscriber access timing window of the small cell base
station 102 into a 0-10 microsecond subscriber access timing
window. In implementations of such an embodiment, an additional
delay of 5 microseconds is added to the 30 microsecond inherent
delay of the distributed antenna system 200 (totaling to a 35
microsecond delay). In such implementations, the extra five
microsecond delay eats into the subscriber access timing window,
because it doesn't radiate until 5 microseconds later, so you have
effectively shrunk the subscriber access timing window for the
remote antenna unit at that particular leg of the distributed
antenna system 200 to 5 microseconds (between 0 and 5 microseconds)
from 10 microseconds (between 0 and 10 microseconds), thereby
reducing the distance D5 accordingly. Thus, by adding additional
delay, the size of the circular coverage area 210 can be
effectively shrunk to facilitate small cells.
In implementations of the digital distributed antenna system 200,
the subscriber access timing window is adjustable, causing the
distance D5 to increase or decrease as the subscriber access timing
window increases or decreases. In such implementations, the
circular coverage area 210 is made smaller by introducing
additional delay into the distributed antenna system 200 to
effectively cut down the size of the circular coverage area 210. In
such implementations, the size of the circular coverage area 210 is
optimized at each remote antenna unit fed off the host unit of the
distributed antenna system 200. In such implementations,
interference from other cells can be reduced by restricting the
size of the circular coverage area 106 and not allowing subscriber
units outside of the specified timing range to access the
system.
In implementations of the digital distributed antenna system 200,
the small cell base station 102 communicates RF signals to and from
the host unit 202 and the host unit 202 converts the RF signals as
appropriate depending on the type of distributed antenna system
200. For example, when the distributed antenna system 200 is a
digital distributed antenna system 200 and the small cell base
station 102 communicates RF signals, the distributed antenna system
200 converts the RF signals into digitized spectrum and transports
that digitized spectrum across a communication link 206 to the
remote antenna unit 204. This communication link 206 may be optical
fiber, coaxial cable, twisted pair, free space media (or other
wireless media) etc. In addition, when the distributed antenna
system 200 is an analog distributed antenna system 200 and the
small cell base station 102 communicates RF signals, the
distributed antenna system 200 converts the RF signals into analog
intermediate frequency (IF) signals and transports those IF signals
across a communication link 206 to the remote antenna unit 204.
This communication link 206 may be optical fiber, coaxial cable,
twisted pair, free space media (or other wireless media), etc. In
addition, when the distributed antenna system 200 is a hybrid
distributed antenna system 200 and the small cell base station 102
communicates RF signals, the distributed antenna system 200
converts the RF signals into digitized spectrum and transports that
digitized spectrum across a communication link 206 to a remote
server unit that converts the digitized spectrum into analog IF
signals and transports the analog IF signals to the remote antenna
unit 204. These communication link 206 may be optical fiber,
coaxial cable, twisted pair, free space media (or other wireless
media), etc.
In implementations of the digital distributed antenna system 200,
the small cell base station 102 communicates digital baseband
signals (such as I/Q information formatted into the characteristic
of an RF channel having a modulation and including in-phase digital
baseband data and quadrature digital baseband data) with the host
unit 202 and the host unit 202 transports the digitized baseband
signals across the communication link 206. For example, when the
distributed antenna system 200 is a digital distributed antenna
system 200 and the small cell base station 102 communicates digital
baseband signals, the master host unit 202 of the distributed
antenna system 200 transports the digital baseband signals across a
communication link 206 to the remote antenna unit 204. In some
implementations, these digital baseband signals are frequency
converted before transmission. This communication link 206 may be
optical fiber, coaxial cable, twisted pair, free space media (or
other wireless media), etc. In addition, when the distributed
antenna system 200 is an analog distributed antenna system 200 and
the small cell base station 102 communicates digitized baseband
signals, the host unit 202 of the distributed antenna system 200
converts the digitized baseband signals to an IF analog signal and
transports the IF analog signal across a communication link 206 to
the remote antenna unit 204. This communication link 206 may be
optical fiber, coaxial cable, twisted pair, free space media (or
other wireless media), etc. In addition, when the distributed
antenna system 200 is a hybrid distributed antenna system 200 and
the small cell base station 102 communicates digital baseband
signals, the host unit 202 of the distributed antenna system 200
transports the digitized baseband signals across a communication
link 206 to the remote antenna unit 204. In some implementations,
these digital baseband signals are frequency converted before
transmission. This communication link 206 may be optical fiber,
coaxial cable, twisted pair, free space media (or other wireless
media), etc.
FIGS. 2B-2C show exemplary embodiments of a system including a
small cell base station 102 coupled with a distributed antenna
system (DAS) 200B having at least one host unit 202 and a plurality
of remote antenna units 204A-204D coupled to the host unit 202 by
communications links 206A-206D respectively. The plurality of
remote units 204 include antennas 208A-208D and circular coverage
area 210A-210D respectively. In implementations of such an
embodiment, each of distances D7, D9, D11, and D13 from the center
of circular coverage areas 210A-210D respectively to the outer
limit of the circular coverage area 210A-210D respectively (the
radius of the circular coverage area 210) provided by the remote
antenna unit 204 is less than about 200 meters. In implementations
of such an embodiment, the distances D7, D9, D11 and D13 relate to
the subscriber access timing window during which the small cell
base station 102 accepts subscriber response described with
reference to FIGS. 1-2 above.
In implementations of such an embodiment, additional delay can be
added to various legs of the distributed antenna system 200B to
further constrict the size of the various circular coverage areas
at various remote antenna units of the various legs of the
distributed antenna system 200B. In such implementations, the
circular coverage areas of the remote antenna units of the various
legs of the distributed antenna system 200B can be tailored to
specific sizes that facilitate appropriate coverage in a particular
area without causing interference to other areas of coverage
provided by remote antenna units of other legs of the distributed
antenna system 200B, remote antenna units from other distributed
antenna systems, small cell base stations, or other types of base
stations.
In the exemplary distributed antenna system 200B of FIG. 2B, each
of circular coverage area 210A-210D are of the same size, meaning
the same total delay of each leg in the distributed antenna system
200B (including the inherent delay and additional delay of each
leg) is equal. In contrast, the exemplary distributed antenna
system 200C of FIG. 2C includes circular coverage areas 210A-210D
of various sizes. Specifically, distance D9 from the center of
circular coverage area 210B is smaller than distances D7 and D11
from the center of circular coverage areas 210A and 210C. In
addition, distance D13 from the center of circular coverage area
210D is greater than distances D7 and D11 from the center of
circular coverage areas 210A and 210C. In implementations of the
digital distributed antenna system 200C, the subscriber access
timing windows of the various legs of the distributed antenna
system 200 have been adjusted, causing the distances D7, D9, D11,
and D13 to change with respect to one another. Thus, in
implementations of the digital distributed antenna system 200C, the
area serviced by remote antenna unit 204B is smaller than the areas
service by remote antenna units 204A and 204C and the areas
serviced by remote antenna units 204A and 204C are smaller than the
area serviced by remote antenna unit 204D. In implementations of
the digital distributed antenna system 200C, the cell size can be
reduced to minimize overlapping areas between cells that can cause
areas of soft handoffs between the coverage areas of a remote
antenna unit in a distributed antenna system and another remote
antenna unit and/or base stations.
Additional delay can be added to digital signals described above by
using buffering of the signals to delay the signals for a set
period of time. In implementations of the digital distributed
antenna system 200C, the host unit 202 includes a single buffer for
all of the legs. In other implementations of the digital
distributed antenna system 200C, the host unit 202 includes a
plurality of buffers for the various legs. Additional delay can be
added to analog signals described above by using loops of fiber
optical cable to add additional length to the propagation of
signals, thereby causing delay.
In exemplary embodiments, the small cell base station 102, host
unit 202, remote antenna units 204A-204D and/or the subscriber
units ensure that sufficient power is provided at the antennas
208A-208D and/or antennas of the subscriber units such that the RF
signal strength of the subscriber at the remote antenna units
204A-204D, the host unit 202, and/or the small cell base station
102 and/or the RF signal strength at the subscriber are acceptable
for proper reception/demodulation of the RF signals. In exemplary
embodiments, the output power level at the small cell base station
102, host unit 202, remote antenna units 204A-204D and/or the
subscriber units is adjusted based on the range of the coverage
areas 210A-210D of the remote antenna units 204A-204D. In some
implementations, the output power level at the antennas 208A-208D
of the remote antenna units 204A-204D and/or the subscriber units
are adjusted proportional to the adjustment of the delay of the
signals to the antennas 208A-208D of the remote antenna units
204A-204D and/or the subscriber units.
A number of embodiments have been described. Nevertheless, it will
be understood that various modifications to the described
embodiments may be made without departing from the spirit and scope
of the claimed invention.
Example Embodiments
Example 1 includes a distributed antenna system comprising: a host
unit communicatively coupled to a first service provider interface
which receives a first signal from the first service provider
interface; a first remote antenna unit communicatively coupled to
the host unit, the first remote antenna unit having a first
antenna; wherein a base station to which the distributed antenna
system is communicatively coupled is configured with a subscriber
access timing window having a minimum allowed delay and a maximum
allowed delay; wherein the distributed antenna system is configured
so that a first total delay between the host unit and the first
remote antenna unit is equal to or greater than the minimum allowed
delay; and wherein the first antenna of the first remote antenna
unit is configured to communicate the first signal to a first
subscriber unit.
Example 2 includes the distributed antenna system of Example 1,
wherein the first total delay comprises at least one of: a first
inherent delay in the distributed antenna system between the host
unit and the first remote antenna unit; a first propagation delay
between the host unit and the first remote antenna unit; and a
first additional configurable delay.
Example 3 includes the distributed antenna system of any of
Examples 1-2, wherein the first total delay comprises a first
configurable delay.
Example 4 includes the distributed antenna system of any of
Examples 1-3, wherein a coverage area of communication from the
first antenna of the first remote antenna unit is proportional to
the first total delay.
Example 5 includes the distributed antenna system of any of
Examples 1-4, wherein a coverage area of communication from the
first antenna of the first remote antenna unit becomes smaller as
the first total delay increases.
Example 6 includes the distributed antenna system of any of
Examples 1-5, wherein the first remote antenna unit is
communicatively coupled to the host unit via a physical medium.
Example 7 includes the distributed antenna system of Example 6,
wherein the physical medium is at least one of a fiber optical
cable, a coaxial cable, or twisted pair.
Example 8 includes the distributed antenna system of any of
Examples 1-7, wherein the first remote antenna unit is
communicatively coupled to the host unit via a wireless medium.
Example 9 includes the distributed antenna system of any of
Examples 1-8, wherein the first service provider interface is
configured to output, and receive as input, respective digital
baseband data; and wherein the first signal is a digital baseband
data signal.
Example 10 includes the distributed antenna system of Example 9,
wherein the digital baseband data comprises in-phase digital
baseband data and quadrature digital baseband data; and wherein the
first signal comprises in phase digital baseband data and
quadrature digital baseband data.
Example 11 includes the distributed antenna system of any of
Examples 9-10, wherein the host unit further comprises a baseband
interface that receives from, and outputs to, the first service
provider interface respective digital baseband data.
Example 12 includes the distributed antenna system of Example 11,
wherein the baseband interface is configured to perform a protocol
conversion between a first baseband protocol used by the first
service provider interface and a second baseband protocol used by
the first remote antenna unit.
Example 13 includes the distributed antenna system of any of
Examples 11-12, wherein the baseband interface is configured to
multiplex digital baseband data.
Example 14 includes the distributed antenna system of any of
Examples 1-13, wherein the first service provider interface is
configured to output, and receive as input, radio frequency
signals; and wherein the first signal is a radio frequency
signal.
Example 15 includes the distributed antenna system of any of
Examples 1-14, wherein the service provider interface interacts
with a carrier network via an Internet protocol (IP) network.
Example 16 includes the distributed antenna system of any of
Examples 1-15, wherein the first remote antenna unit is
communicatively coupled to the host unit via at least one
intermediary device.
Example 17 includes the distributed antenna system of Example 16,
wherein the intermediary device comprises an expansion hub.
Example 18 includes the distributed antenna system of any of
Examples 16-17, wherein the distributed antenna system is a hybrid
distributed antenna system; wherein the intermediary device
comprises a remote server unit that interfaces between a digital
portion of the distributed antenna system and an analog portion of
the distributed antenna system; wherein the digital portion of the
distributed antenna system includes digital communication between
the host unit and the remote server unit; wherein the remote server
unit converts between digital and analog signals; and wherein the
analog portion of the distributed antenna system includes analog
communication between the remote server unit and the first remote
antenna unit.
Example 19 includes the distributed antenna system of any of
Examples 1-18, wherein the distributed antenna system is configured
to distribute multiple services.
Example 20 includes the distributed antenna system of any of
Examples 1-19, wherein the distributed antenna system is coupled to
multiple wireless service providers' networks.
Example 21 includes the distributed antenna system of any of
Examples 1-20, wherein the distributed antenna system is configured
for use in at least one of: in-building applications, outdoor
applications, enterprise applications, public safety applications,
and military applications.
Example 22 includes the distributed antenna system of any of
Examples 1-21, further comprising groups of the remote antenna
units that are configurable for local joint beamforming and/or
joint transmission groups of cells.
Example 23 includes the distributed antenna system of any of
Examples 1-22, further comprising: a second remote antenna unit
communicatively coupled to the host unit, the second remote antenna
unit having a second antenna; wherein the distributed antenna
system is configured so that a second total delay between the host
unit and the second remote antenna unit is equal to or greater than
the minimum allowed delay; and wherein the second antenna of the
second remote antenna unit is configured to communicate the first
signal to a second subscriber unit.
Example 24 includes the distributed antenna system of Example 23,
wherein the second total delay comprises at least one of: a second
inherent delay in the distributed antenna system between the host
unit and the second remote antenna unit; a second propagation delay
between the host unit and the second remote antenna unit; and a
second additional configurable delay.
Example 25 includes the distributed antenna system of any of
Examples 23-24, wherein a coverage area of communication from the
second antenna of the second remote antenna unit is proportional to
the second total delay.
Example 26 includes the distributed antenna system of any of
Examples 23-25, wherein the second remote antenna unit is
communicatively coupled to the host unit via a physical medium.
Example 27 includes the distributed antenna system of Example 26,
wherein the physical medium is at least one of a fiber optic cable,
a coaxial cable, or twisted pair.
Example 28 includes the distributed antenna system of any of
Examples 1-27, further comprising: wherein the host unit is further
communicatively coupled to a second service provider interface
which receives a second signal from the second service provider
interface; and wherein at least one antenna of the first remote
antenna unit is configured to communicate the second signal to a
second subscriber unit.
Example 29 includes the distributed antenna system of Example 28,
wherein the second service provider interface is configured to
output, and receive as input, respective digital baseband data; and
wherein the second signal is a digital baseband data signal.
Example 30 includes the distributed antenna system of any of
Examples 28-29, wherein the second service provider interface is
configured to output, and receive as input, radio frequency
signals; and wherein the second signal is a radio frequency
signal.
Example 31 includes the distributed antenna system of any of
Examples 28-30, wherein the second remote antenna unit is
communicatively coupled to the host unit via at least one
intermediary device.
Example 32 includes the distributed antenna system of any of
Examples 1-31, further comprising: wherein the host unit is further
communicatively coupled to a second service provider interface
which receives a second signal from the service provider interface;
a second remote antenna unit communicatively coupled to the host
unit, the second remote antenna unit having a second antenna;
wherein the distributed antenna system is configured so that a
second total delay between the host unit and the second remote
antenna unit is equal to or greater than the minimum allowed delay;
and wherein the second antenna of the second remote antenna unit is
configured to communicate the second signal to a second subscriber
unit.
Example 33 includes the distributed antenna system of Example 32,
wherein the second total delay comprises at least one of: a second
inherent delay in the distributed antenna system between the host
unit and the second remote antenna unit; a second propagation delay
between the host unit and the second remote antenna unit; and a
second additional configurable delay.
Example 34 includes the distributed antenna system of any of
Examples 32-33, wherein the second remote antenna unit is
communicatively coupled to the host unit via a physical medium.
Example 35 includes the distributed antenna system of any of
Examples 32-34, wherein the second service provider interface is
configured to output, and receive as input, respective digital
baseband data; and wherein the second signal is a digital baseband
data signal.
Example 36 includes the distributed antenna system of any of
Examples 32-35 wherein the second service provider interface is
configured to output, and receive as input, radio frequency
signals; and wherein the second signal is a radio frequency
signal.
Example 37 includes the distributed antenna system of Example 32,
wherein the second remote antenna unit is communicatively coupled
to the host unit via at least one intermediary device.
Example 38 includes the distributed antenna system of Example 37,
wherein the distributed antenna system is a hybrid distributed
antenna system; wherein the intermediary device comprises a remote
server unit that interfaces between a digital portion of the
distributed antenna system and an analog portion of the distributed
antenna system; wherein the digital portion of the distributed
antenna system includes digital communication between the host unit
and the second remote server unit; wherein the remote server unit
converts between digital and analog signals; and wherein the analog
portion of the distributed antenna system includes analog
communication between the remote server unit and the second remote
antenna unit.
Example 39 includes a method comprising: configuring a distributed
antenna system to have a first additional delay in addition to a
first inherent delay of the distributed antenna system between a
host unit and a first remote antenna unit; wherein the distributed
antenna system is communicatively coupled to a base station
configured with a subscriber access timing window having a minimum
allowed delay and a maximum allowed delay; and wherein a first
total delay of the first additional delay and the first inherent
delay of the distributed antenna system is equal to or greater than
the minimum allowed delay.
Example 40 includes the method of Example 39, wherein the first
inherent delay comprises at least one of a propagation delay
between the host unit and the first remote antenna unit.
Example 41 includes the method of any of Examples 39-40, wherein a
coverage area of communication from a first antenna of the first
remote antenna unit is proportional to the first total delay.
Example 42 includes the method of any of Examples 39-41, further
comprising transporting signals from the base station through the
distributed antenna system via a physical medium.
Example 43 includes the method of any of Examples 39-42, further
comprising communicating digital baseband data between a service
provider interface of the base station and the host unit of the
distributed antenna system.
Example 44 includes the method of any of Examples 39-43, further
comprising communicating radio frequency signals between a service
provider interface of the base station and the host unit of the
distributed antenna system.
Example 45 includes the method of any of Examples 39-44, further
comprising: configuring a distributed antenna system to have a
second additional delay in addition to a second inherent delay of
the distributed antenna system between the host unit and a second
remote antenna unit; and wherein a second total delay of the second
additional delay and the second inherent delay of the distributed
antenna system is equal to or greater than the minimum allowed
delay.
Example 46 includes a distributed antenna system comprising: a host
unit communicatively coupled to a first service provider interface
which receives a first signal from the first service provider
interface; a first remote antenna unit communicatively coupled to
the host unit; wherein a base station to which the distributed
antenna system is communicatively coupled is configured with a
subscriber access timing window having a minimum allowed delay and
a maximum allowed delay; and wherein the distributed antenna system
is configured so that a first total delay between the host unit and
the first remote antenna unit is equal to or greater than the
minimum allowed delay.
* * * * *