U.S. patent application number 13/533522 was filed with the patent office on 2012-10-18 for methods and apparatus for resolving identifier conflicts in a communication system.
This patent application is currently assigned to QUALCOMM INCORPORATED. Invention is credited to Parag Arun Agashe, Pranav Dayal, Alexei Gorokhov, Rajat Prakash, Fatih Ulupinar.
Application Number | 20120263032 13/533522 |
Document ID | / |
Family ID | 39864883 |
Filed Date | 2012-10-18 |
United States Patent
Application |
20120263032 |
Kind Code |
A1 |
Prakash; Rajat ; et
al. |
October 18, 2012 |
METHODS AND APPARATUS FOR RESOLVING IDENTIFIER CONFLICTS IN A
COMMUNICATION SYSTEM
Abstract
Apparatus and methods of allocating identifiers in a
communication system include receiving, at a first access point, a
set of physical layer identifiers used by a plurality of access
points, with assistance from an access terminal. The apparatus and
methods further include detecting, relative to one of the plurality
of access points, a conflicting physical layer identifier.
Additionally, the apparatus and methods include selecting, at the
first access point, a first physical layer identifier distinct from
the conflicting physical layer identifier.
Inventors: |
Prakash; Rajat; (La Jolla,
CA) ; Gorokhov; Alexei; (San Diego, CA) ;
Ulupinar; Fatih; (San Diego, CA) ; Agashe; Parag
Arun; (San Diego, CA) ; Dayal; Pranav; (San
Diego, CA) |
Assignee: |
QUALCOMM INCORPORATED
San Diego
CA
|
Family ID: |
39864883 |
Appl. No.: |
13/533522 |
Filed: |
June 26, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12171479 |
Jul 11, 2008 |
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13533522 |
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60950094 |
Jul 16, 2007 |
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Current U.S.
Class: |
370/216 |
Current CPC
Class: |
H04L 5/0001 20130101;
H04W 72/0426 20130101 |
Class at
Publication: |
370/216 |
International
Class: |
H04L 12/26 20060101
H04L012/26 |
Claims
1. A method for allocating identifiers in a communication system,
comprising: receiving, at a first access point, a set of physical
layer identifiers used by a plurality of access points, with
assistance from an access terminal; detecting, relative to one of
the plurality of access points, a conflicting physical layer
identifier; and selecting, at the first access point, a first
physical layer identifier distinct from the conflicting physical
layer identifier.
2. The method as defined in claim 1, wherein the conflicting
physical layer identifier indicates one of two or more access
points utilizing an identical physical layer identifier or two or
more access points having physical layer identifier offsets
insufficient to enable distinguishing between the respective
physical layer identifiers of the two or more access points.
3. The method as defined in claim 1, wherein the first physical
layer identifier is a same physical layer identifier as an original
physical layer identifier allocated to the one of the at least two
access points having the conflicting physical layer identifier.
4. The method as defined in claim 1, further comprising: selecting
at least one second physical layer identifier for use by at least
one remaining access point having the conflicting physical layer
identifier, wherein the at least one second physical layer
identifier is selected to be distinct from all physical layer
identifiers used by the one or more of the plurality of access
points.
5. The method as defined in claim 1, wherein the plurality of
access points includes at least a first tier network of the first
access point and a second tier network in a vicinity of the first
access point.
6. The method as defined in claim 1, wherein the first physical
layer identifier is a new randomly selected physical layer
identifier.
7. The method as defined in claim 1, wherein the assistance from
the access terminal comprises: a message from the access terminal
reporting the conflicting physical layer identifier when detected
by the access terminal.
8. The method as defined in claim 4, further comprising:
transmitting at least one message to the at least one remaining
access point having the conflicting physical layer identifier
including instructions to change to the second physical layer
identifier.
9. The method as defined in claim 1, further comprising: deriving
from an active set of access points identified in a response from
the access terminal at least one of the one or more of a plurality
of access points.
10. The method as defined in claim 5, further comprising: sending a
message from the first access point to a second access point
requesting neighboring second tier access points known to the
second access point, wherein the first access point and the second
access point are included in the plurality of access points.
11. The method as defined in claim 11, wherein the message is sent
over a backhaul network.
12. The method as defined in claim 10, wherein the plurality of
access points comprise a union of access points known to the first
access point, first tier neighbors of the first access point, and
second tier neighbors of the first access point.
13. The method as defined in claim 1, wherein the selecting of the
first physical layer identifier further comprises selecting based
on a characteristic of the one or more of the plurality of access
points.
14. The method as defined in claim 13, wherein selecting based on
the characteristic further comprises selecting based on a number of
users being served or based on a coverage area.
15. The method as defined in claim 4, further comprising: obtaining
a set of second tier physical layer identifiers used by a second
tier set of access points neighboring the first access point; and
wherein the selecting of the at least one second physical layer
identifier is further distinct from the set of second tier physical
layer identifiers.
16. The method as defined in claim 1, wherein the detecting of the
conflicting physical layer identifier further comprises detecting
that two or more of the plurality of access points have physical
layer identifier offsets insufficient to enable distinguishing
between the respective physical layer identifiers of the two or
more of a plurality of access points.
17. An apparatus for use in a communication system comprising:
means for receiving, at a first access point, a set of physical
layer identifiers used by a plurality of access points, with
assistance from an access terminal; means for detecting, relative
to one of the plurality of access points, a conflicting physical
layer identifier; and means for selecting, at the first access
point, a first physical layer identifier distinct from the
conflicting physical layer identifier.
18. The apparatus as defined in claim 17, wherein the conflicting
physical layer identifier indicates one of two or more access
points utilizing an identical physical layer identifier or two or
more access points having physical layer identifier offsets
insufficient to enable distinguishing between the respective
physical layer identifiers of the two or more access points.
19. The apparatus as defined in claim 17, wherein the first
physical layer identifier is a same physical layer identifier as an
original physical layer identifier allocated to the one of the at
least two access points having the conflicting physical layer
identifier.
20. The apparatus as defined in claim 17, further comprising: means
for selecting at least one second physical layer identifier for use
by at least one remaining access point having the conflicting
physical layer identifier, wherein the at least one second physical
layer identifier is selected to be distinct from all physical layer
identifiers used by the one or more of the plurality of access
points.
21. The apparatus as defined in claim 17, wherein the plurality of
access points includes at least a first tier network of the first
access point and a second tier network in a vicinity of the first
access point.
22. The apparatus as defined in claim 17, wherein the first
physical layer identifier is a new randomly selected physical layer
identifier.
23. The apparatus as defined in claim 17, wherein the assistance
from the access terminal comprises: means for receiving a message
from the access terminal reporting the conflicting physical layer
identifier when detected by the access terminal.
24. The apparatus as defined in claim 20, further comprising: means
for transmitting at least one message to the at least one remaining
access point having the conflicting physical layer identifier
including instructions to change to the second physical layer
identifier.
25. The apparatus as defined in claim 17, further comprising: means
for deriving from an active set of access points identified in a
response from the access terminal at least one of the one or more
of a plurality of access points.
26. The apparatus as defined in claim 21, further comprising: means
for sending a message from the first access point to a second
access point requesting neighboring second tier access points known
to the second access point, wherein the first access point and the
second access point are included in the plurality of access
points.
27. The apparatus as defined in claim 26, wherein the message is
sent over a backhaul network.
28. The apparatus as defined in claim 25, wherein the plurality of
access points comprise a union of access points known to the first
access point, first tier neighbors of the first access point, and
second tier neighbors of the first access point.
29. An apparatus for use in allocating identifiers in a
communication network, comprising: a processor for: receiving, at a
first access point, a set of physical layer identifiers used by a
plurality of access points, with assistance from an access
terminal; detecting, relative to one of the plurality of access
points, a conflicting physical layer identifier; and selecting, at
the first access point, a first physical layer identifier distinct
from the conflicting physical layer identifier; and a memory
coupled to the processor.
30. A program recorded on a non-transitory computer recordable
medium and executable on a computer, comprising: code for causing
the computer to receive, at a first access point, a set of physical
layer identifiers used by a plurality of access points, with
assistance from an access terminal; code for causing the computer
to detect, relative to one of the plurality of access points, a
conflicting physical layer identifier; and code for causing the
computer to select, at the first access point, a first physical
layer identifier distinct from the conflicting physical layer
identifier.
Description
CLAIM OF PRIORITY
[0001] The present Application for Patent is a continuation of
patent application Ser. No. 12/171,479, entitled "Method and
Apparatus for Resolving Pilot Pseudorandom Noise Code Conflicts in
a Communication System," filed Jul. 11, 2008, pending, and further
claims priority to Provisional Application No. 60/950,094, entitled
"Automated Procedure for PilotPN Planning in Wireless Communication
Networks," filed Jul. 16, 2007, both assigned to the assignee
hereof and both hereby expressly incorporated by reference
herein.
BACKGROUND
[0002] 1. Field
[0003] The present disclosure generally relates to methods and
apparatus for resolving identifier conflicts in a communication
system.
[0004] 2. Background
[0005] In wireless communication systems, such as an Ultra Mobile
Broadband (UMB) system, identification information such as a pilot
pseudorandom noise code (referred to herein as a "PilotPN code" or
simply "PilotPN") is used to identify an access point (AP) or base
station to an access terminal (AT) or other user equipment.
Ideally, each PilotPN for each respective AP is unique.
Nonetheless, even if the same PilotPN is used for more than one AP,
each PilotPN emanating from a particular AP may have a PN offset
different from the counterpart emanating from the another AP to
achieve differentiation. If these are not the case, however, a
PilotPN conflict scenario may arise. Sometimes, the term "PilotPN
conflict" is called a "PilotPN collision" instead. For purposes of
this disclosure, the two terms are used interchangeably.
[0006] Any PilotPN conflict is undesirable as repeating or even
closely offset PilotPNs from different APs can disrupt signal
demodulation, decoding, and further network side routing. In order
to resolve PilotPN conflict, the occurrence of PilotPN collision
has previously been resolved by manual intervention and
coordination, which results in increased costs and deployment
delays. In accordance with the present disclosure, such collision
or conflict may be resolved automatically through PilotPN planning
as will be described herein.
SUMMARY
[0007] According to an aspect, a method for allocating identifiers
in a communication system is disclosed. The method includes
receiving, at a first access point, a set of physical layer
identifiers used by a plurality of access points, with assistance
from an access terminal. The method further includes detecting,
relative to one of the plurality of access points, a conflicting
physical layer identifier. Further, the method includes selecting
at the first access point, a first physical layer identifier
distinct from the conflicting physical layer identifier.
[0008] According to another aspect, an apparatus for use in
allocating identifiers in a communication network is disclosed. The
apparatus includes at least one processor that is configured to
receive, at a first access point, a set of physical layer
identifiers used by a plurality of access points, with assistance
from an access terminal; detect, relative to one of the plurality
of access points, a conflicting physical layer identifier; and
select at the first access point, a first physical layer identifier
distinct from the conflicting physical layer identifier. The
apparatus also includes a memory coupled to the at least one
processor.
[0009] According to still a further aspect, an apparatus for use in
a communication system is disclosed. The apparatus includes means
for receiving, at a first access point, a set of physical layer
identifiers used by a plurality of access points, with assistance
from an access terminal. Also, the apparatus includes means for
detecting, relative to one of the plurality of access points, a
conflicting physical layer identifier. Additionally, the apparatus
includes means for selecting, at the first access point, a first
physical layer identifier distinct from the conflicting physical
layer identifier.
[0010] According to yet one further aspect, a computer program
product is disclosed that includes a computer-readable medium. The
computer-readable medium includes code for causing a computer to
receive, at a first access point, a set of physical layer
identifiers used by a plurality of access points, with assistance
from an access terminal. The medium also includes code for causing
the computer to detect, relative to one of the plurality of access
points, a conflicting physical layer identifier. Additionally, the
medium includes code for causing the computer to select, at the
first access point, a first physical layer identifier distinct from
the conflicting physical layer identifier.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is an illustrative example of a first tier
communication system, which may employ the presently disclosed
methods and apparatus for PilotPN planning and conflict
resolution.
[0012] FIG. 2 is an illustrative example of a first tier
communication system, which may employ the presently disclosed
methods and apparatus for PilotPN planning and conflict
resolution.
[0013] FIG. 3 is a call flow diagram of an exemplary method for
resolving conflicts between PilotPNs in a communication system.
[0014] FIG. 4 is a call flow diagram of another exemplary method
for resolving conflicts between PilotPNs in a communication
system.
[0015] FIG. 5 is a flowchart diagram of an exemplary method that
may be used to resolve conflicts between PilotPNs in a
communication system.
[0016] FIG. 6 is an exemplary apparatus that may be utilized in an
access point or similar device for resolving conflicts between
PilotPNs in a communication system.
[0017] FIG. 7 is another example of an apparatus that may be
utilized in an access terminal or similar device for resolving
conflicts between PilotPNs in a communication system.
[0018] FIG. 8 is yet another example of an apparatus that may be
used to resolve conflicts between PilotPNs in a communication
system.
DETAILED DESCRIPTION
[0019] The presently disclosed method and apparatus effect
resolving pilot pseudorandom noise (PN) code conflicts in a
communication system. In particular, the present disclosure relates
to methods and apparatus for automated planning of PilotPN codes to
resolve PilotPN conflicts through the assistance of access terminal
(ATs) communicating PilotID information to access points (APs). It
is noted here that the presently disclosed method and apparatus may
be viewed in relation to automated neighbor discovery (ND) of
access terminals in a communication system, such as was disclosed
in U.S. application Ser. No. 12/136,495, filed Jun. 10, 2008
entitled "METHODS AND APPARATUS FOR NEIGHBOR DISCOVERY OF BASE
STATIONS IN A COMMUNICATION SYSTEM" by Tinnakornsrisuphap et al.,
assigned to the assignee hereof, and is expressly incorporated by
reference herein.
[0020] In the following described examples, for reasons of
conciseness and clarity the disclosure uses terminology associated
with Ultra Mobile Broadband (UMB) technology. It should be
emphasized, however, that the presently described examples are also
applicable to other technologies, such as technologies related to
Code Division Multiple Access (CDMA), Time Division Multiple Access
(TDMA), Frequency Division Multiple Access (FDMA), Orthogonal
Frequency Division Multiple Access (OFDMA) and so forth. It will be
appreciated by those skilled in the art, that when applying the
disclosed methods and apparatus to other technologies, the
associated terminology would clearly be different.
[0021] As pedagogical background concerning collision types, it is
noted that in certain communication systems there are two types of
collisions that may occur, namely, first-tier collisions and
second-tier collisions. FIG. 1 illustrates a communication system
in which a first-tier collision may occur. In the first-tier
collision scenario, an AT 102 may be in a coverage area of two
access points (APs). A first access point AP1 104 may be part of a
sector having a SectorID of SectorIDa, as an example, and a second
access point AP2 106 is in another sector with a SectorID of
SectorIDb. In this example, however, AP1 and AP2 are assumed to
both transmit the same PilotPN code, thus resulting in a conflict
or collision between two PilotPNs. It is also noted that the
PilotPN of each AP 104, 106 need not be identical to cause a
conflict, but instead the PN offset may be configured in such a way
that it is difficult for the AT 102 to differentiate the
difference, thus engendering a conflict.
[0022] Using another example to describe a second-tier conflict,
FIG. 2 illustrates another communication system in which a
second-tier collision situation may arise. In this example, the
communication includes a first access point AP1 202, a second
access point AP2 204, and a third access point AP3 206. In the
system of FIG. 2, a situation that may give rise to a second-tier
collision is when AP2 204 and AP3 206 transmit the same
PilotPN.
[0023] As shown in FIG. 2, a first access terminal AT1 208 and a
second access terminal AT2 210 are in a coverage territory of AP1
202 as indicated by wireless links 212 and 214, respectively. It is
intended that AT1 208 sense the PilotPN from AP2 204, while the AT2
210 sees the PilotPN from the AP3. Suppose, however, that AT1 208
tries to communicate a message to the AP2 204 though the AP1 202
via a backhaul network (not shown), for example, for reserving
resources on AP2. The AT1 208 would then use the PilotPN (or
SectorID information) to resolve an address (e.g., an IP address)
in order to route such a message via the backhaul. However, the AP1
202 in this case is unable to decide to which access point, i.e.,
AP2 204 or the AP3 206, the message is to be forwarded. Quite
likely, AP1 202 is unaware of the existence of the AP3 206 and thus
mistakenly forwards the message to the AP3 206 via the
backhaul.
[0024] In order to resolve conflicts, such as the first and second
tier conflicts discussed above, the present application discloses
methods and apparatus for resolving conflicts dues to conflicting
PilotPNs. According to an aspect, FIG. 3 illustrates a call flow
diagram 300 of a methodology that may effect PilotPN conflict
resolution in a communication system, such as the systems of FIGS.
1 and 2. An access point AP1 302 may currently serve one or more
access terminals, such as shown access terminal AT 304, as an
example. AP1 302 may then be configured to periodically probe or
query various ATs currently served by AP1 302, as shown by block
306 in order to determine whether two access points in the same
region share the same PilotPN.
[0025] To accomplish this end, an access point, such as AP1 302,
may be configured to periodically send a request message to one or
more ATs within its coverage area requesting the SectorIDs, and
thus APs, contained in the active sets of the AT's. Message
SectorIDRequest 308 from AP1 302 to AT 304 is shown in FIG. 3 as an
example. In response to message 308, the AP1 302 receives message
reports from the ATs, such as SectorIDResponse 310 from AT 304 as
an example. In the particular example of FIG. 3, the response 310
may include a Sector ID of SectorIDb and a PilotPN code PNb that
pertain to another access point AT2 312 from which AT1 304 receives
or has received signal strength.
[0026] The access point receiving the messages (e.g., AP1 302) may
then perform detection of PilotPN conflicts from a set of access
points or SectorIDs (termed herein as set S.sub.SID) as indicated
by block 314. The set of access points is obtained or determined by
the querying of the ATs by AP1 302. According to an aspect, a set
of PilotPNs (termed herein as set S.sub.PN) used within the set of
access points (i.e., the set S.sub.SID) may then be obtained or
determined from the queried ATs. If there exists at least two
different SectorIDs or APs that have conflicting PilotPNs (i.e.,
they share the same PilotPN code), the AP1 302 may then be
configured to contact one of the APs having a conflicting PilotPN
over the backhaul and request a change of PilotPN. Alternatively,
mediation may occur by a predetermined access point where the
mediator detects the conflicting PilotPN codes and subsequently
allocates the PilotPN values for respective APs and communicates
the new allocated PilotPN values to the affected APs. These
processes are illustrated in the example of FIG. 3 by arrow 316,
where communication between AP1 302 and AP2 312. Afterward, the
conflict between PilotPNs has been resolved as indicated by block
318. As yet another alternative, it is noted that AP1 302 may
change its own PilotPN rather than contacting the other APs as
illustrated in FIG. 3.
[0027] It is noted that in an aspect the AP1 302, if acting as a
mediating AP, may be configured to pick PilotPNs that are not being
used by any of the known first-tier or second-tier neighbors. In a
further aspect, AP1 302 may find out about the set of PilotPNs that
are used by the second-tier neighbors by requesting its neighbors
(e.g., first tier neighbors) for information about their neighbors
(i.e., second tier neighbors with respect to the requesting AP),
such as over the backhaul. Such querying affords the avoidance of
PilotPN collisions with both first and second tier neighbors.
Furthermore, it is noted that if multiple iterations are being
performed (i.e., the processes of the call flow in FIG. 3 are
repeated multiple times), the new distinct PilotPN will not be used
or allocated in any of the subsequent iterations.
[0028] According to alternative example, an AT may be configured to
initiate autonomously or independently the collision detection and
reporting processes. Referring to the call diagram of FIG. 4, as an
example, an AT 402 detects two APs 404, 406 in its vicinity having
the same PilotPN as indicated by block 408. In this example, the AT
402 may detect more than one AP with the same PilotPN but having
different SectorIDs in a predetermined time window, which can be
network configured, for example, as illustrated by block 410. The
AT would then send a SectorIDReport message 412 to any accessible
AP (e.g., serving AP1 404 in this example), in which information
regarding the conflicting PilotPN, the Sector IDs of the
conflicting APs (if known), signal strength, and the time of
measurement (if known) is included. It also should be noted that
the additional fields of the SectorIDReport message could be
included in response to a SectorIDRequest message from an AP as an
alternative (thus the message would be a responsive message). The
AP receiving message 412 would then initiate PilotPN mediation
according to the processes discussed above with respect to FIG.
3.
[0029] FIG. 5 illustrates a flow diagram of a method 500 for
automated allocation of PilotPNs in a communication system. As
shown, the method includes a block 502 where a set of a plurality
of APs (e.g. S.sub.SID) is determined. As noted above, the set of
all APs or SectorIDs may be derived with the assistance of one or
more ATs served by a particular AP. As also discussed above,
particular implementations may include the set of APs being
determined within an AP, as shown in FIG. 3, or alternatively being
determined by one or more ATs as described in connection with FIG.
4.
[0030] After the set of APs is determined, flow proceeds to block
504 where a set of PilotPN codes (e.g., S.sub.PN) used by the set
of the plurality of access points is determined or defined. Again,
implementation of the process or functions of block 504 may be
effected in a number of alternative devices. In one aspect, this
set of PilotPNs may be determined within an AP, such as in the
procedure shown in FIG. 3. In an alternative aspect, set S.sub.PN
may be determined by one or more ATs, as described in connection
with FIG. 4.
[0031] After determination of the set in block 504, flow proceeds
to block 506 where detection is made whether at least two access
points of the plurality of access points have conflicting PilotPN
codes. According to one particular implementation of the process of
block 506, a subset (termed herein as S.sub.2) of APs within the
set of access points (i.e., S.sub.SID) may be selected of APs
having a distinct PilotPN from the set S.sub.PN of PilotPNs. It is
noted that since only one occurrence of a PilotPN is allowed for
each AP, the number of APs in subset S.sub.2 will be equal to the
number PilotPNs. Thus, if the subset S.sub.2 is less than the
number of APs in set S.sub.SID, it can be deduced that conflicting
PilotPNs are extant.
[0032] As an example of subset S.sub.2 selection, assume three
distinct SectorIDs or APs numbered AP1, AP2, and AP3 are extant in
set S.sub.SID. The set S.sub.PN of PilotPNs, however, only contains
two distinct PilotPNs PN1 and PN2, where PN1 is assumed associated
with APs AP1 and AP2 and PN2 is associated with AP3. Accordingly,
the subset S.sub.2 could contain AP1 and AP3, or alternatively AP2
and AP3 for the occurrences of PN1 and PN2. Accordingly, it is can
then be known that there is a conflict concerning multiple uses of
PilotPN PN1. Stated another way, the APs in subset S.sub.2 may then
be allocated respective PilotPNs from the set S.sub.PN. Thus, it is
evident that by excluding allocation of extant PilotPNs to those
remaining APs having shared PilotPNs, a determination of a conflict
has been identified, as well as determining or identifying those
APs that will need to have their PilotPN codes changed.
[0033] Similar to the processes of blocks 502 and 504, the
processes of block 506 may be effected by various alternate
devices. In one aspect, the process of block 506 may be implemented
in an AP, such as in the procedure shown in FIG. 3. In an
alternative aspect, the processes of block 506 may be determined by
one or more ATs, such as was described in connection with FIG. 4.
Additionally, if the processes of block 506 are implemented by an
AT, the AT may be configured to autonomously send a message to an
AP reporting the conflicting PilotPNs where the message is
triggered when the conflicting Pilot PNs are determined by the AT.
In yet a further alternative, various processes of block 506 may be
respectively implemented by an AP and one or more ATs.
[0034] After block 506, flow proceeds to block 508 where a first
PilotPN code is allocated to one of the at least two APs having
conflicting PilotPN codes. Thus, in the particular example from
above, AP1 and AP2 have conflicting PilotPN codes (e.g., PN1).
Thus, one of AP1 or AP2 could remain allocated with PN1 as the
first PilotPN code. Continuing with this example, this allocation
may consist of selecting one of AP1 or AP2 to be a member of subset
S.sub.2, whereas the other AP (or APs in the case of more than two
conflicting PNs) would be excluded from the subset. It is noted
that the decision of which AP is selected for subset S.sub.2 may be
arbitrary. Alternatively, the decision of which APs to exclude may
be based on various criteria, such as the number of users currently
served by an AP or the coverage area of the APs. Concerning the
first PilotPN code, it is noted that the first PilotPN code could
also consist of an entirely new PilotPN code.
[0035] Method 500 also includes allocating at least a second
PilotPN code distinct from the first PilotPN code to at least one
remaining access point of the at least two access points having
conflicting PilotPN codes as illustrated by block 510. Given the
above example, the one or more remaining access points excluded
from subset S.sub.2 (i.e., S.sub.SID-S.sub.2) are assigned or
allocated with respective other second PilotPN codes outside of the
set S.sub.PN of PilotPNs. It is noted that the processes of block
510 may be implemented by AP communication to the other APs on a
backhaul to effect the change in the PilotPNs, as one example. It
is also contemplated that this messaging may also take place via
wireless links, such as between APs if within range and the APs
including AT equipment or an equivalent. Additionally, it is
contemplated that AT devices could also assist in such messaging
over wireless links.
[0036] It is also noted that selection of PilotPNs for some or all
of the APs could be random and distinct PilotPNs outside the set
S.sub.PN. It is also contemplated, however, that selection could
further alternatively be based on a survey of all second tier AP
PilotPNs and then selecting PilotPNs outside of that set of PNs.
This alternative aspect is further illustrated by the operation of
block 512, which is shown dashed accordingly. As may be seen in the
example of block 512, a query may be issued by an AP (or AT
initiated as a further option) to its first tier neighbor APs
during the operation of block 502, for example, to determine second
tier neighbor APs when determining the set of the plurality of APs
(and the attendant PilotPN codes). This query may be accomplished
via messaging over the backhaul, as an example, but could also be
accomplished wirelessly via ATs, for example. Accordingly, the set
of the plurality of APs and the set of PilotPN codes will account
for second tier neighbors when allocating the first PilotPN and the
at least second Pilot PN in the operation of blocks 508 and 510. It
is further noted that the process 500 may be periodic in nature to
effect an iterative algorithm or method for planning or changing
PilotPNs in a communication system. In addition, while, for
purposes of simplicity of explanation, the methodology is shown and
described as a series or number of acts, it is to be understood
that the processes described herein are not limited by the order of
acts, as some acts may occur in different orders and/or
concurrently with other acts from that shown and described herein.
For example, those skilled in the art will appreciate that a
methodology could alternatively be represented as a series of
interrelated states or events, such as in a state diagram.
Moreover, not all illustrated acts may be required to implement a
methodology in accordance with the subject methodologies disclosed
herein.
[0037] FIG. 6 schematically shows an exemplary implementation of an
apparatus 600 for executing the methodologies as described above.
Apparatus 600 may be implemented in a server implemented with an
AP, as merely an example, or any other suitable apparatus.
Apparatus 600 may also be implemented as other suitable hardware
(e.g., processor, or a collection of circuits/modules), software,
firmware, or any combination thereof for use in an AT device
[0038] The apparatus 600 features a central data bus 602, or
similar device for communicatively linking several circuits or
modules together. The circuits may include a CPU (Central
Processing Unit) or a controller 604 and transceiver circuits 606.
The apparatus 600 may also include a memory unit 610 or similar
device for storing computer or processor executable
instructions.
[0039] The transceiver circuits 606 include receiver circuits to
process received signals before sending out to the central data bus
602, as well as transmit circuits to process and buffer data from
the data bus 602 before sending out of the device 600, such as to
one or more ATs. Additionally in the case where apparatus 600 is
employed in an AP or base station, the transceiver circuits 606 may
include RF circuits to transmit and receive via a wireless link 612
to the one or more AT's.
[0040] The CPU/controller 604 may be configured to perform the
function of data management of the data bus 602 and further perform
the function of general data processing, including executing the
instructional contents of the memory unit 610. It is noted here
that instead of separately implemented as shown in FIG. 6, as an
alternative, the transceiver circuits 606 can be incorporated as
parts of the CPU/controller 604. As a further alternative, the
entire apparatus 600 may be implemented as an application specific
integrated circuit (ASIC) or similar apparatus.
[0041] The memory unit 610 may include one or more sets of
instructions/modules. In the exemplary apparatus 600, the
instructions/modules include, among other things, a PilotPN
Conflict Detection and Resolution function 614, which is configured
to effect the methodologies described herein. Memory unit 610 may
further include other data constructs or structures that store,
among other things, the PilotPN and AP (SectorID) data derived from
ATs or other APs.
[0042] In the example of FIG. 6, the memory unit 610 may be a RAM
(Random Access Memory) circuit. The exemplary portions, such as the
function 614, are software routines, modules and/or data sets. The
memory unit 610 can be tied to another memory circuit (not shown)
which either can be of the volatile or nonvolatile type. As an
alternative, the memory unit 610 can be made of other circuit
types, such as an EEPROM (Electrically Erasable Programmable Read
Only Memory), an EPROM (Electrical Programmable Read Only Memory),
a ROM (Read Only Memory), an ASIC (Application Specific Integrated
Circuit), a magnetic disk, an optical disk, and other
computer-readable media well known in the art.
[0043] It is further noted that the apparatus 600 may alternatively
include network interface circuits 608 or similar devices that may
be used to effect communication of PilotPN information to other
APs, such as via a backhaul 616. In particular, the circuits 608
may be used to transmit and receive messages for either receiving
or sending PilotPN information to other APs for changing PilotPNs
in those APs having conflicting PilotPNs.
[0044] FIG. 7 illustrates another exemplary apparatus 700 that may
be utilized to effect the methodologies disclosed herein. It is
noted that apparatus 700 may constitute an AT or other suitable
hardware (e.g., processor, or a collection of circuits/modules),
software, firmware, or any combination thereof for use in an AT
device. As illustrated, the apparatus 700 includes a central data
bus 702, or similar device for communicatively linking or coupling
several circuits together. The circuits include a CPU (Central
Processing Unit) or a controller 704, transceiver circuits 706,
network, and a memory unit 708.
[0045] The transceiver circuits 706 include receiver circuits to
process received signals before sending out to the central data bus
702, as well as transmit circuits to process and buffer data from
the data bus 702 before sending out of the device 700, such as to
one or more APs as illustrated by wireless communication link(s)
710. Accordingly, the transceiver circuits 706 may include RF
circuits to transmit over the wireless link 710 to the one or more
ATs.
[0046] The CPU/controller 706 performs the function of data
management of the data bus 702 and further the function of general
data processing, including executing the instructional contents of
the memory unit 710. It is noted here that instead of separately
implemented as shown in FIG. 7, as an alternative, the transceiver
circuits 706 can be incorporated as parts of the CPU/controller
704. As a further alternative, the entire apparatus 700 may be
implemented as an application specific integrated circuit (ASIC) or
similar apparatus.
[0047] The memory unit 710 may include one or more sets of
instructions/modules. In the exemplary apparatus 700, the
instructions/modules include, among other things, a PilotPN
Conflict Detection and Resolution function 712, which is configured
to effect the methodologies described herein; namely the processes
of either of call flow diagrams in FIGS. 3 and 4, as well as one or
more processes of the method 500 disclosed in FIG. 5. It is also
noted that memory unit 710 may store an active set or list of all
APs with which the AT device has visited. This active set may then
be used by either an AP (or AT) to derive the set of all APs;
namely S.sub.SID discussed above.
[0048] In the example of FIG. 7, the memory unit 710 may be a RAM
(Random Access Memory) circuit. The exemplary portions, such as the
function 714, are software routines, modules and/or data sets. The
memory unit 710 can be tied to another memory circuit (not shown)
which either can be of the volatile or nonvolatile type. As an
alternative, the memory unit 710 can be made of other circuit
types, such as an EEPROM (Electrically Erasable Programmable Read
Only Memory), an EPROM (Electrical Programmable Read Only Memory),
a ROM (Read Only Memory), an ASIC (Application Specific Integrated
Circuit), a magnetic disk, an optical disk, and other
computer-readable media well known in the art.
[0049] FIG. 8 illustrates another apparatus 800 for use in a
communication system that may be utilized for resolving PilotPN
collisions or conflicts. It is noted that the apparatus 800, may be
implemented in an AP, as one example. It should be further noted,
that disclosed apparatus 800 is not limited to implementation only
in an AP, but may transcend implementation solely in an AP by also
including implementation of the disclosed functional means or
modules, or portions thereof, in one or more AT devices.
[0050] Apparatus 800 includes a module or means 802 for determining
a set of a plurality of APs (e.g. S.sub.SID). It is noted that
module 802 may be implemented by both components or modules within
an AP as well as components or modules in one or more ATs.
Furthermore, the module 802 may be implemented with components in
the AP that initiate queries to various ATs in its coverage area,
as well as components in one or more ATs that respond with PilotPN
information to the querying AP as was discussed previously in
connection with the call flow diagram in FIG. 3. Alternatively, the
module 802 may also be implemented with components in an AP and ATs
that are configured to implement the call flow of FIG. 4 where one
or more AT devices serve to initiate the function of determining
the set of the plurality of APs. The information received by module
802 may then be communicated to various other modules or means in
apparatus 800 via a bus 804, or similar suitable communication
coupling.
[0051] It is also contemplated, however, that selection by module
802 could further be implemented with the assistance or addition of
an alternative module or means 805 that affords the determination
to be based on a survey of all second tier AP PilotPNs and then
selecting PilotPNs outside of that set of PNs. Module 805 for
determining second tier neighbors from first tier neighbors effects
initiation of a query that may be issued by an AP (or AT initiated
as a further option) to its first tier neighboring APs via a
backhaul, as an example, to obtain information of neighboring APs
known to those APs, which are second tier neighbors to apparatus
800. From the second tier APs, module 805 then also assists in the
determination of a set of the attendant PilotPN codes. Thus, the
addition of the functionality of module 805 may ensure that the set
of the plurality of APs and the set of PilotPN codes will account
for second tier neighbors when allocating the first PilotPN and the
at least second Pilot PN codes.
[0052] The set of APs (and associated PilotPNs) may be communicated
by module 802 to a module or means 806 for determining a set of
PilotPN codes (e.g., S.sub.PN) used by the set of the plurality of
access points. Module 806 may be implemented, as an example, by
components within an AP, an AT, or a combination thereof. Exemplary
functions that may be employed by module 806 include the functions
described above in connection with FIGS. 3, 4 and 5.
[0053] Apparatus 800 further includes a module or means 808 for
detecting whether at least two access points of the plurality of
access points have conflicting PilotPN codes based on the sets
determined by modules 802 and 806, for example. Similar to modules
802 and 806, this module 808 may be implemented, as an example, by
components within an AP, an AT, or a combination thereof. Exemplary
functions that may be employed by module 806 include the functions
described above in connection with FIGS. 3, 4 and 5.
[0054] Apparatus 800 also includes a module or means 810 for
allocating a first PilotPN code to one of the at least two access
points having conflicting PilotPN codes. A module 812 is also
featured for allocating at least a second PilotPN code distinct
from the first PilotPN code to at least one remaining access point
of the at least two access points having conflicting PilotPN codes.
It is noted that modules 810 and 812 may be implemented within or
by an AP, as an example. It is further noted that either of these
modules may be configured to communicate allocated PilotPN codes to
one or more other APs in order to effect changes to the PilotPNs of
those APs selected to have their PNs changed.
[0055] In addition, the apparatus 800 may include an optional
computer readable medium or memory device 814 configured to store
computer readable instructions and data for effecting the processes
and behavior of one or more of the modules in apparatus 800.
Additionally, apparatus 800 may include a processor 816 configured
to execute the computer readable instructions in memory 814, and
thus may be configured to execute one or more functions of the
various modules in apparatus 800.
[0056] In light of the above discussion, it can be appreciated that
the presently disclosed methods and apparatus afford automated
planning/conflict resolution for PilotPN codes in a communication
system. It is noted that by iterative or periodic discovery of APs
and associated PilotPNs, conflicts between PilotPNs may be
effectively discovered before an actual PilotPN collision occurs.
It will also be appreciated by those skilled in the art that the
present methods and apparatus are thus effective in mitigating the
adverse effects of such collisions on operations such as signal
demodulation, decoding, and further network side routing.
[0057] It is understood that the specific order or hierarchy of
steps in the processes disclosed is an example of exemplary
approaches. Based upon design preferences, it is understood that
the specific order or hierarchy of steps in the processes may be
rearranged while remaining within the scope of the present
disclosure. The accompanying method claims present elements of the
various steps in a sample order, and are not meant to be limited to
the specific order or hierarchy presented.
[0058] Those skilled in the art will appreciate that information
and signals may be represented using any of a variety of different
technologies and techniques. For example, data, instructions,
commands, information, signals, bits, symbols, and chips that may
be referenced throughout the above description may be represented
by voltages, currents, electromagnetic waves, magnetic fields or
particles, optical fields or particles, or any combination
thereof.
[0059] Those skilled in the art will further appreciate that the
various illustrative logical blocks, modules, circuits, and
algorithm steps described in connection with the embodiments
disclosed herein may be implemented as electronic hardware,
computer software, or combinations of both. To clearly illustrate
this interchangeability of hardware and software, various
illustrative components, blocks, modules, circuits, means, and
steps have been described above generally in terms of their
functionality. Whether such functionality is implemented as
hardware or software depends upon the particular application and
design constraints imposed on the overall system. Those skilled in
the art may implement the described functionality in varying ways
for each particular application, but such implementation decisions
should not be interpreted as causing a departure from the scope of
the present disclosure.
[0060] The various illustrative logical blocks, modules, and
circuits described in connection with the embodiments disclosed
herein may be implemented or performed with a general purpose
processor, a digital signal processor (DSP), an application
specific integrated circuit (ASIC), a field programmable gate array
(FPGA) or other programmable logic device, discrete gate or
transistor logic, discrete hardware components, or any combination
thereof designed to perform the functions described herein. A
general purpose processor may be a microprocessor, but in the
alternative, the processor may be any conventional processor,
controller, microcontroller, or state machine. A processor may also
be implemented as a combination of computing devices, e.g., a
combination of a DSP and a microprocessor, a plurality of
microprocessors, one or more microprocessors in conjunction with a
DSP core, or any other such configuration.
[0061] The steps of a method or algorithm described in connection
with the embodiments disclosed herein may be embodied directly in
hardware, in a software module executed by a processor, or in a
combination of the two. A software module may reside in RAM memory,
flash memory, ROM memory, EPROM memory, EEPROM memory, registers,
hard disk, a removable disk, a CD-ROM, or any other form of storage
medium known in the art. An exemplary storage medium (not shown)
may be coupled to the processor such the processor can read
information from, and write information to, the storage medium. In
the alternative, the storage medium may be integral to the
processor. The processor and the storage medium may reside in an
ASIC. The ASIC may reside in a user terminal. In the alternative,
the processor and the storage medium may reside as discrete
components in a user terminal.
[0062] The examples described above are merely exemplary and those
skilled in the art may now make numerous uses of, and departures
from, the above-described examples without departing from the
inventive concepts disclosed herein. Various modifications to these
examples may be readily apparent to those skilled in the art, and
the generic principles defined herein may be applied to other
examples, e.g., in an instant messaging service or any general
wireless data communication applications, without departing from
the spirit or scope of the novel aspects described herein. Thus,
the scope of the disclosure is not intended to be limited to the
examples shown herein but is to be accorded the widest scope
consistent with the principles and novel features disclosed herein.
It is noted that the word "exemplary" is used exclusively herein to
mean "serving as an example, instance, or illustration." Any
example described herein as "exemplary" is not necessarily to be
construed as preferred or advantageous over other examples.
Accordingly, the novel aspects described herein are to be defined
solely by the scope of the following claims.
* * * * *