U.S. patent application number 14/277348 was filed with the patent office on 2014-09-04 for load distribution in a network of small-cell base stations.
This patent application is currently assigned to Google Inc.. The applicant listed for this patent is Google Inc.. Invention is credited to Milo Steven Medin, Siddharth Ray, Murari Srinivasan.
Application Number | 20140247724 14/277348 |
Document ID | / |
Family ID | 50187493 |
Filed Date | 2014-09-04 |
United States Patent
Application |
20140247724 |
Kind Code |
A1 |
Ray; Siddharth ; et
al. |
September 4, 2014 |
Load Distribution in a Network of Small-Cell Base Stations
Abstract
A network device may make a determination that a first backhaul
connection, which serves a first base station, is congested and
that a second backhaul connection, which serves a second base
station, is not congested. This determination may be made based on
a first periodic data cap imposed on the first backhaul connection,
a traffic load on the first backhaul connection, a second periodic
data cap imposed on the second backhaul connection, and a traffic
load on the second backhaul connection. In response to the
determination, the network device may configure a value of a
cellular communication parameter utilized by one or both of the
base stations. The configuration may comprise periodic adjustments
of the value of the cellular communication parameter. The periodic
adjustments may cause one or more mobile devices to be cyclically
handed-over between the first base station and the second base
station.
Inventors: |
Ray; Siddharth; (Palo Alto,
CA) ; Srinivasan; Murari; (Palo Alto, CA) ;
Medin; Milo Steven; (Redwood City, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Google Inc. |
Mountain View |
CA |
US |
|
|
Assignee: |
Google Inc.
Mountain View
CA
|
Family ID: |
50187493 |
Appl. No.: |
14/277348 |
Filed: |
May 14, 2014 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
13604748 |
Sep 6, 2012 |
8761021 |
|
|
14277348 |
|
|
|
|
Current U.S.
Class: |
370/235 |
Current CPC
Class: |
H04W 84/045 20130101;
H04W 36/22 20130101; H04W 36/00837 20180801; H04W 28/0247 20130101;
H04W 92/045 20130101; H04W 28/08 20130101; H04W 16/08 20130101;
H04W 24/08 20130101 |
Class at
Publication: |
370/235 |
International
Class: |
H04W 28/08 20060101
H04W028/08; H04W 36/22 20060101 H04W036/22 |
Claims
1. A method comprising: in a network device of a first service
provider, determining that a first backhaul connection, which
serves a first base station, is congested and that a second
backhaul connection, which serves a second base station, is not
congested, the determining being made based on a first periodic
data cap imposed on the first backhaul connection, a traffic toad
on the first backhaul connection, a second periodic data cap
imposed on the second backhaul connection, and a traffic load on
the second backhaul connection; in response to determining that the
first backhaul connection is congested and the second backhaul
connection is not congested, configuring a value of a cellular
communication parameter utilized by one or both of the first base
station and the second base station, wherein the configuring
results in one or more mobile devices being handed-over from the
first base station to the second base station.
2. The method of claim 1, wherein: configuring the value of the
cellular communication parameter comprises periodic adjustments of
the value of the cellular communication parameter; and the periodic
adjustments of the value of the cellular communication parameter
causes one or more mobile devices to be repeatedly handed-over
between the first base station and the second base station.
3. The method of claim 1, further comprising retrieving the first
periodic data cap and the second periodic data cap from a database
that stores constraints on backhaul connections.
4. A method comprising: performing by a network device: determining
a load state of each of a plurality of network connections,
wherein: each of the plurality of network connections backhaul a
respective one of a plurality of base stations; and for each one of
the plurality of network connections, the determining of the load
state is based on a periodic data cap imposed on the one of the
plurality of network connections; and configuring one or more of
the plurality of base stations based on the determined load state
of each of the plurality of network connections.
5. The method of claim 4, wherein the configuring one or more of
the plurality of base stations comprises adjusting a value of a
parameter such that traffic is redistributed from a
more-heavily-loaded one of the plurality of network connections to
a less-heavily-loaded one of the plurality of network
connections.
6. The method of claim 5, wherein said parameter comprises one or
more of the following: minimum quality of service level, whether to
accept inbound handovers, or whether to initiate outbound
handovers.
7. The method of claim 4, wherein: the configuring one or more of
the plurality of base stations comprises periodically adjusting of
one or more parameter values; and the periodic adjusting of one or
more parameter values causes one or more mobile devices to be
cyclically handed-over among the plurality of base stations.
8. The method of claim 4, wherein the configuring one or more of
the plurality of base stations comprises one or both of: reducing a
power at which the one or more of the plurality of base stations
transmit on a cellular channel; and decreasing a sensitivity with
which the one or more of the plurality of base stations listen on a
cellular channel.
9. The method of claim 4, wherein the configuring one or more of
the plurality of base stations comprises transmitting one or more
network management messages over one or both of: the plurality of
backhaul connections; and one or more connections that are
out-of-band with the plurality of backhaul connections.
10. The method of claim 4, wherein the configuring one or more of
the plurality of base stations results in a handover of a mobile
device from a first one of the plurality of the base stations to a
second one of the plurality of the base stations.
11. The method of claim 4, wherein: cellular connections handled by
the plurality of base stations are associated with one or more
first service providers; and the plurality of network connections
are associated with one or more second service providers.
12. The method of claim 4, wherein one or more of the plurality of
network connections carry data communicated between non-base
station devices in addition to carrying data communicated to and/or
from a respective one of the plurality of base stations.
13. A system comprising: a network device operable to: determine a
load state o each of a plurality of network connections, wherein:
each of the plurality of network connections backhauls a respective
one of a plurality of base stations; and for each one of the
plurality of network connections, the determining of the load state
is based on a periodic data cap imposed on the one of the plurality
of network connections; and configure one or more of the plurality
of base stations based on the determined load state.
14. The system of claim 13, wherein the configuring comprises
adjusting a value of a parameter such that traffic is redistributed
from a more-heavily-loaded one of the plurality of network
connections to a less-heavily-loaded one of the plurality of
network connections.
15. The system of claim 13, wherein: the configuration of one or
more of the plurality of base stations comprises periodic
adjustments of one or more parameter values; and the periodic
adjustments of one or more parameter values causes one or more
mobile devices to be cyclically handed-over among the plurality of
base stations.
16. The system of claim 13, wherein the configuration of one or
more of the plurality of base stations comprises one or both of: a
reduction of a power at which the one or more of the plurality of
base stations transmit on a cellular channel; and a reduction of a
sensitivity with which the one or more of the plurality of base
stations listen on a cellular channel.
17. The system of claim 13, wherein the configuration of one or
more of the plurality of base stations comprises configuration of a
value of one or more of the following parameters: minimum quality
of service level, whether to accept inbound handovers, or whether
to initiate outbound handovers.
18. The system of claim 13, wherein the configuration of one or
more of the plurality of base stations comprises transmission of
one or more network management messages over one or both of: the
plurality of backhaul connections; and one or more connections that
are out-of-band e plurality of backhaul connections.
19. The system of claim 13, wherein the configuration of one or
more of the plurality of base stations results in a handover of a
mobile device from a first one of the plurality of the base
stations to a second one of the plurality of the base stations.
20. The system of claim 13, wherein: cellular connections handled
by the plurality of base stations are associated with one or more
first service providers; and the plurality of network connections
are associated with one or more second service providers.
21. The system of claim 13, wherein one or more of the plurality of
network connections carry data communicated between non-base
station devices in addition to carrying data communicated to and/or
from a respective one of the plurality of base stations.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This U.S. patent application is a continuation of, and
claims priority under 35 .sctn.120 from, U.S. patent application
Ser. No. 13/604,748, filed on Sep. 6, 2012, which is hereby
incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] Aspects of the present application relate to wireless
communications. More specifically, to a method and apparatus for
load distribution in a network of small-cell base stations.
BACKGROUND
[0003] Deploying small-cell (e.g., femtocell) base stations in
homes and businesses may present challenges not faced in the
deployment of macrocell base stations. Further limitations and
disadvantages of conventional and traditional approaches will
become apparent to one of skill in the art, through comparison of
such approaches with some aspects of the present method and
apparatus set forth in the remainder of this disclosure with
refrence to the drawings.
SUMMARY
[0004] A method and/or apparatus is provided for wireless
communications, substantially as illustrated by and/or described in
connection with at least one of the figures, as set forth more
completely in the claims
[0005] The details of one or more implementations of the disclosure
are set forth in the accompanying drawings and the description
below. Other aspects, features, and advantages will be apparent
from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
[0006] FIG. 1A depicts an example of a network comprising a
plurality of small-cell base stations backhauled over data-capped
network connections.
[0007] FIG. 1B depicts an example of a network comprising a
plurality of small-cell base stations.
[0008] FIG. 1C is a block diagram of an example base station
manager,
[0009] FIG. 1D is an example of a data structure utilized for load
distribution in a network of small-cell base stations,
[0010] FIGS. 2A and 2B illustrate reconfiguration of a cell
boundary in response to one backhaul connection becoming
more-heavily loaded than another.
[0011] FIGS. 3A and 3B illustrate an example configuration and
reconfiguration of parameter values to traffic load distribution in
a network of small-cell base stations.
[0012] FIG. 4 illustrates a cyclical handing over of a mobile
device for traffic load distribution among a plurality of backhaul
connections.
[0013] FIG. 5 illustrates communication of network management
messages for managing traffic loads on backhaul connections of
small-cell base stations.
[0014] FIG. 6 is a flowchart illustrating steps for load
distribution in a network of small-cell base stations.
[0015] Like refrence symbols in the various drawings indicate like
elements.
DETAILED DESCRIPTION
[0016] As utilized herein the terms "circuits" and "circuitry"
refer to physical electronic components (i.e. hardware) and any
software and/or firmware ("code") which may configure the hardware,
be executed by the hardware, and or otherwise be associated with
the hardware. Hardware may comprise, for example, one or more
processors, ASICs, and/or FPGAs. As utilized herein, "and/or" means
any one or more of the items in the list joined by "and/or". As an
example, "x and/or y" means any element of the three-element set
{(x), (y), (x, y)}. As another example, "x, y, and/or z" means any
element of the seven-element set {(x), (y), (z), (x, y), (x, z),
(x,y,z)}. As utilized herein, the terms "block" and "module" refer
to functions than can be performed by one or more circuits. As
utilized herein, the term "e.g.," introduce a list of one or more
non-limiting examples, instances, or illustrations.
[0017] in an example implementation, a network device of a first
service provider may make a determination that a first backhaul
connection, which serves a first base station, is congested and
that a second backhaul connection, which serves a second base
station, is not congested. This determination may be made based on,
for example, a first periodic data cap imposed (e.g., by a second
service provider) on the first backhaul connection, a traffic load
on the first backhaul connection, a second periodic data cap
imposed (e.g., by a second service provider) on the second backhaul
connection, and a traffic load on the second backhaul connection.
In response to the determination, the network device may configure
a value of a cellular communication parameter utilized by one or
both of the base stations. The configuration may result in one or
more mobile devices being handed-over from the first base station
to the second base station. The configuration may also comprise
periodic adjustments of the value of the cellular communication
parameter. The periodic adjustments may cause one or more mobile
devices to be cyclically handed-over between the first base station
and the second base station.
[0018] FIG. 1A depicts an example of a network comprising a
plurality of small-cell base stations backhauled over data-capped
network connections. The network 100 comprises base stations 102a,
102b, and 124; and subnetworks 106a, 106b, and 110.
[0019] The subnetwork 110 may be a core network of a service
provider that provides network access to mobile devices. The
subnetwork 110 may be, for example, a core network 110 of a
cellular service provider. The core network 110 may comprise
various components 112 (e.g., routers, switches, hubs, etc.) for
connecting the core network to the access networks 106a and 106b
and to the base station 124. The core network 110 may comprise a
base station manager 114 which may operate as described herein.
[0020] Each of the base stations 102a and 102b may be operable to
communicate data between mobile devices and a respective one of the
subnetworks 106a and 106b, In this regard, base station 102a may
communicate data between mobile device 202a and the subnetwork
106a, and base station 102b may communicate data between mobile
device 202b and subnetwork 106b. In this regard, each of the base
stations 102a and 102b may support any one or more wireless (e.g.,
Wi-Fi, LTE), wired (e.g., Ethernet, DSL), and/or optical (e.g.,
Fibre Channel) protocols. Each of the base stations 102a and 102b
may comprise circuitry operable to implement functions of a base
station described herein.
[0021] In an example implementation, the base stations 102a and
102b may be associated with the cellular provider that is
associated with the core network 110. In this regard, one or more
agreements may be in place between the owner(s) of the base
stations 102a and 102b such that the base stations 102a and 102b
are permitted to communicate on frequencies owned/leased by the
cellular provider.
[0022] The connection 104a through the subnetwork 106a may carry
backhaul traffic for the base station 102a. The connection 104b
through the subnetwork 106b may carry backhaul traffic for the base
station 102b. Each of the connections 104a and 104b may comprise
one or more wired, wireless, and/or optical network links.
[0023] Each of the subnetworks 106a and 106b may be an access
network of a respective Internet service provider (ISP).
Accordingly, each of the base stations 102a and 102b may be
associated with a contract between a subscriber and an ISP that
provides one of the access networks 106a and 106b. The subnetwork
106a may be, for example, an access network of a cable television
provider, where the owner and/or lessee of the base station 102a
has an account with the cable television provider, and the base
station 102a is associated with the contract. The subnetwork 106b
may be, for example, an access network of an xDSL provider, where
the owner and/or lessee of the base station 102b has an account
with the xDSL provider, and the base station 102b is associated
with the contract.
[0024] In an example implementation, the cellular provider may not
have control, or at least not sole control, over the access
networks 106a and 106b. For example, the ISPs associated with the
access networks 106a and 106b may be separate entities than the
cellular provider associated with the core network 110.
Consequently, restrictions, such as periodic data caps and/or
maximum traffic loads, imposed on the connections 104a and 104b may
be, at least partially, out of the control of the cellular
provider. Periodic data caps may be measured in, for example, bits
or bytes. A traffic load may be measured in, for example, bits or
bytes per unit time (e.g., megabits per second (Mbps) or megabytes
per second (MBps)). A traffic load may be, for example, an
instantaneous traffic load at one or more time instants, an average
traffic toad averaged over a time period (e.g., an hour, day, week,
month, year, or billing period), and/or an average traffic load
broken down by category (e.g., by time of day, time of week, and/or
time of year).
[0025] The base station manager 114 may be operable to collect
information about the backhaul connections 104a and 104b and
utilize the information for managing via a logical management
interface between it and the base station 102a and/or between it
and the base station 102b) the respective traffic loads on the base
stations 102a and 102b. The collected information may be stored in
a data structure, such as the one described below with respect to
FIG. 1D, which may be part of, and/or accessible by, the base
station manager 114. Collected information may be, for example,
updated continuously, periodically, and/or on an event-driven
basis. The base station manager 114 may comprise circuitry which
resides in a single device or is distributed among a plurality of
devices. In this regard, although an example implementation is
depicted in which the base station manager 114 resides entirely in
the core network 110, the base station manager 114 could reside
entirely or partly in any one or more of the base station 102a, the
base station 102b, and the core network 110.
[0026] Managing the respective traffic loads on the base stations
102a and 102b may comprise configuring one or both of the base
stations 102a and 102b, by, for example, configuring a value of one
or more parameters utilized by one or both of the base stations
102a and 102b. The parameters may include, for example: transmit
power, receive sensitivity, channels to utilize, one or more
quality of service (QoS) thresholds above and/or below which
traffic is to be accepted and/or dropped, identifiers of permitted
and/or denied traffic flows, whether particular base stations may
accept inbound handovers, whether particular base stations should
initiate outbound handovers, and/or any other parameters useful for
managing the respective traffic loads on the base stations 102a and
102b.
[0027] Additionally or alternatively, configuring one or both of
the base stations 102a and 102b may comprise communication of
network management messages. Such messages may be communicated, for
example, between the base stations 102a and 102b, between the base
station 102a and the core network 110 (e.g., components 112 and/or
the base station manager 114), and/or between the base station 102b
and the core network 110 (e.g., components 112 and/or the base
station manager 114). The network management messages may be
communicated in-band and/or out-of-band with one or both of the
connections 104a, as is described below with respect to FIG. 5.
[0028] The collected information may include, for example, one or
more maximum permitted traffic loads for the connection 104a (which
may be imposed by the ISP that provides connection 104a), and/or a
one or more maximum permitted traffic loads for the connection 104b
(which may be imposed b the ISP that provides connection 104b). For
example, the ISP that provides connection 104a may impose a maximum
downstream load of 50 Mbps, and a maximum upstream load of 10
Mbps.
[0029] The collected information may, for example, include a
periodic data cap imposed on the connection 104a, and/or a periodic
data cap imposed on the connection 104b. For example, the ISP that
provides connection 104a may impose a monthly data cap of 250 GB
and the ISP that provides connection 104b may impose a monthly data
cap of 300 GB. In some instances, the periodic data cap and the
maximum load of a connection may be interrelated. For example, the
ISP that provides connection 104a may impose a maximum of 50 Mbps
up to the first 250 GB in a billing cycle and a maximum load of 10
Mbps for amounts in excess of 250 GB in a single billing cycle.
[0030] The collected information may include, for example, a total
amount of traffic communicated over the connection 104a during one
or more time periods, and/or a total amount of traffic communicated
over the connection 104b during one or more time periods. A time
period may be, for example, an hour, day, week, month, year, and/or
billing period (e.g., the billing period for subscriber's contract
with an ISP). In some instances, the total amount of traffic may
include only traffic that counts towards a subscriber's periodic
allotment. For example, the ISP that provides connection 104a may
impose a monthly data cap of 250 GB, but only DOCSIS data may count
toward that allotment while cable television programming may not
count toward the 250 GB allotment.
[0031] The collected information may include, for example, the
traffic load on one or both of the connections 104a and 104b. For
example, a current instantaneous traffic load and/or an average
traffic load over a current, in-progress time period may be
collected for each of the connections 104a and 104b.
[0032] The base station manager 114 may collect (e.g., via a
logical management interface accessible by the base stations 102a
and 102, the components 112, and/or other devices) information
about the connections 104a and/or 104b through the communication of
management messages with other network devices (e.g., the base
stations 102a and 102b, devices in the access networks 106a and
106b, and/or devices in the core network 110). For example, other
devices may collect information as traffic arrives at and/or
traverses them. Such devices may communicate such collected
information to the base station manager 114 on a periodic or
event-driven basis (e.g., in response to a request from the base
station manager 114). Additionally or alternatively, the management
messages may comprise probe messages utilized to measure various
network information.
[0033] operation, the base stations 102a and 102b may communicate
data to and/or from mobile devices (e.g., 202a and 202b) utilizing
cellular protocols (e.g., LTE). Such data may be backhauled to
and/or from the core network 110 via a respective one of network
connections 104a and 104b. Values of one or more parameters
utilized by the base stations 102a and 102b may be configured by
the base station manager 114 in order to manage respective traffic
loads on the base stations 102a and 102b. The configuration of the
parameters may be based on collected information about the
respective traffic loads on the backhaul connections 104a and
104b.
[0034] The collected information may be utilized to determine the
load state of the connections 104a and 104b. That is, utilized to
determine a traffic load on each of the connections 104a and 104b,
and to categorize those loads into one of a finite number of load
states. Such categorization may be accomplished by comparing the
traffic loads to one or more thresholds. In a single threshold
implementation, for example, a connection may be determined to be
first load state (e.g., a "congested" state) if its traffic load
exceeds the threshold and in a second load state (e,g., a "not
congested" state) if its traffic load is below the threshold. The
determination of a load state of the connections 104a and 104b may,
for example, be made periodically and/or made occasionally in
response to a triggering event or condition.
[0035] In an example single-threshold implementation, the threshold
for categorizing a load state may, for example, be calculated as
shown below in EQ 1.
LT=(D-B)/T EQ. 1
where `T` is the load threshold measured in bits per unit `D` is
the periodic data cap measured in bits, `B` is the total amount of
data consumed over the connection during the current time period
(measured in bits), and `T` is the amount of time remaining in the
current time period. In such an instance, the connection may be
determined to be in a first load state if the traffic load is
greater than LT and a second load state if the traffic load is less
than LT.
[0036] In an example N-threshold implementation (where N is an
integer greater than 1), the thresholds for determining a load
state may, for example, be calculated as shown below in EQ 2.
[LT.sub.1, LT.sub.2, . . . LT.sub.N]=((D-B)/T)[S.sub.1, S.sub.2, .
. . S.sub.N] EQ. 2
where `[LT.sub.1, LT.sub.2, . . . LT.sub.N]` is an array of N load
thresholds measured in bits per unit time, `D` is the periodic data
cap measured in bits, `B` is the total amount of data consumed over
the connection during the current time period (measured in bits),
`T` is the amount of time remaining in the current time period, and
[S.sub.1, S.sub.2, . . . S.sub.N] is an array of scaling factors
where S.sub.1>S.sub.2> . . . >S.sub.N. For example, if
N=2, then a load greater than LT.sub.1 may correspond to a first
load state, a load between LT.sub.1 and LT.sub.2 may correspond to
a second load state (a relatively lower traffic load than the first
state), and a load below LT.sub.2 may correspond to a third load
state (a relatively lower traffic load than the second load
state).
[0037] In an example single-threshold implementation, the threshold
for categorizing a load state may, for example, be calculated as
shown below in EQ 3.
LT=(S)(M) EQ. 3
where `LT` is the load threshold measured in bits per unit time,
`S` is a scaling factor, and `M` is a maximum permitted load of the
connection.
[0038] In an example N-threshold implementation (where N is an
integer greater than 1), the thresholds for determining a load
state may, for example, be calculated as shown below in EQ 4.
[LT.sub.1, LT.sub.2, . . . LT.sub.N]=[S.sub.1, S.sub.2, . . .
S.sub.N](M) EQ. 4
where `[LT.sub.1, LT.sub.2, . . . LT.sub.N]` is an array of N load
thresholds measured in bits per unit time, "M' is a maximum
permitted load of the connection, and [S.sub.1, S.sub.2, . . .
S.sub.N] is an array of scaling factors where
S.sub.1>S.sub.2> . . . >S.sub.N. For example, if M=2, then
a load greater than LT.sub.1 may correspond to a first load state,
a load between LT.sub.1 and LT.sub.2 may correspond to a second
load state (a relatively lower traffic load than the first state),
and a load below LT.sub.2 may correspond to a third load state (a
relatively lower traffic load than the second load state).
[0039] FIG. 1B depicts an example of a network comprising a
plurality of small-cell base stations. In the network 150 depicted
in FIG. 1B, again shown are the base stations 102a and 102b, the
connections 104a and 104b, the subnetwork 110, and the base station
manager 114. Additionally, network devices 152 and 158 and network
links 154 and 156 are shown.
[0040] The network device 152 may comprise a non-base station
device such as, for example, a laptop or desktop computer that is
not configured to function as a base station. The device 152 may
reside within a premises 160 (e.g., a residence, business or public
venue) along with the base station 102a. The device 152 may
comprise circuitry operable to implement functions of the network
device 152 described herein.
[0041] The network device 158 may comprise a non-base station
device such as, for example, a router or network switch that is not
configured to function as a base station, which may communicate
with the base station 102a and non-base station device 152 via
network links 154 and 156 respectively. The network device 158 may
reside within the premises 160 along with the base station 102a.
The network device 158 may comprise circuitry operable to implement
functions of the network device 158 described herein.
[0042] The connection 104a may provide an internet connection to
the premises 160. Thus, the connection 104a may carry data to
and/or from both the base station 102a and the non-base station
device 152. Data to and/or from the network device 152 may
comprise, for example, website data, file uploads, file downloads,
and/or any other traffic which a residence and/or business may
communicate to and/or from the Internet. Because data to and/or
from the base station 102a shares the connection 104a with data to
and/or from the non-base station device 152, the latter may be
accounted for by the base station manager 114 when collecting
information about the connection 104a and/or when determining a
load state of the connection 104a. For example, where the
respective cellular traffic loads on the base stations 102a and
102b are roughly equal, but device 152 is generating a lot of
traffic, connection 104a may be in a more-heavily loaded state than
connection 104b. Accordingly, the base station manager 114 may take
action to redistribute the existing loads (e.g., through handovers
and/or traffic filtering) and/or to balance the respective loads
going forward (e.g., encourage or force new connections to be
established with the base station 102b rather than the base station
102, where possible.).
[0043] In addition to routing/switching/bridging traffic between
the connection 104a and the links 154 and 156, the network device
158 may perform and/or aid in the collection of information about
the connection 104a. In this regard, the network device 158 may be
a component of the base station manager 114 and/or may exchange
network management messages with the base station manager 114.
[0044] FIG. 1C is a block diagram of an example base station
manager. In the example implementation depicted, the circuitry of
the base station manager 114 comprises a transceiver 116, a CPU
118, and a memory 120.
[0045] The transceiver 116 may be operable to communicate in
accordance with one or more communications protocols for
communicating over wired, wireless, and/or optical links. The
transceiver 116 may, for example, communicate utilizing the
Internet protocol suite (including TCP and/or IP).
[0046] The CPU 118 may be operable to effectuate operation of the
base station manager 114 by executing lines of code stored in the
memory 120. Such lines of code may include, for example, one or
more programs for implementing an interface for collecting and
analyzing network information to generate decisions regarding the
management of network traffic.
[0047] The memory 120 may comprise program memory, run-time memory,
and/or mass storage. The memory 120 may, for example, comprise
non-volatile Memory, volatile memory, read only memory (ROM),
random access memory (RAM), flash memory, magnetic storage, and/or
any other suitable memory. Program memory may store lines of code
executable by the CPU 118 to effectuate operation of network
management actions. Runtime memory may store data generated and/or
used during execution of the network management programs. For
example, runtime memory may store values utilized in evaluating,
and/or the results of evaluating, equations 1-3 above. Mass storage
may, for example, store data that becomes too large for efficient
storage in runtime memory For example, collected information
regarding connections 104a and 104b may be stored in mass storage
in a data structure 122 and portions of that data may be loaded
into runtime memory as needed. An example of the data structure 122
is described below with reference to FIG. 1D.
[0048] FIG. 1D is an example of a data structure utilized for load
distribution in a network of small-cell base stations. Each of the
entries 190.sub.1-190.sub.N (where `N` is an integer and `n` is a
value between 1 and `N`) in the data structure 122 is associated
with a particular backhaul connection and comprises current
conditions of (e.g. traffic load) and/or constraints on (e.g., data
rate limit and/or periodic data cap) the particular backhaul
connection. In the implementation depicted, each entry 190
comprises: a field 172 which stores an identifier associated with a
particular backhaut connection, a field 174 which stores the total
amount of data consumed over the connection during a time period
(e.g., the current month or a previous month), a field 176 which
stores the periodic data cap imposed on the connection, a field 178
which stores an amount of time left in the time period, afield 180
which stores a traffic load on the connection, and afield 182 which
stores a maximum load imposed on the connection. Each of the fields
in FIG. 1D is populated with arbitrary values to illustrate how the
stored values may be utilized to determine a load state of a
connection.
[0049] Table 1 below illustrates example load state determinations
made utilizing equation 1 above,
TABLE-US-00001 TABLE 1 Load State Determination using EQ. 1
Connection LT L Load state 170a 15 MBps 7 MBps Not congested 170b 5
MBps 7 MBps Congested 170c 20 MBps 9 MBps Not congested 170d 20
MBps 10 MBps Not congested
[0050] Thus, table 1 illustrates an example scenario in which
connection 170b is determined to be congested as a result of the
fact that, based on its traffic load, L, the connection 170b will
exceed its periodic data cap for the time period. The consequences
of exceeding the data cap may depend on policies of the service
provider that provides the connection 170c, but such consequences
could include, for example, the connection 170c being disabled or a
data rate of the connection 170c being throttled down. The loss of
connection 170c would result in a base station that is backhauled
by the connection 170c being unable to provide service to mobile
devices. This, in turn, could result in a "hole" or "dead zone" in
the cellular provider's coverage. Accordingly, the base station
manager 114 may take action to attempt to reduce the load on the
connection 170c.
[0051] Table 2 below illustrates example load state determinations
utilizing equation 3 above and a hypothetical scaling factor, S, of
0.8. The scaling factor may be configured by the cellular provider
based, for example, on performance data (e.g., load variance,
traffic latency, dropped packets, etc.). By using a scaling factor
0.8, 20% headroom is reserved for handling transient traffic
spikes, for example.
TABLE-US-00002 TABLE 2 Load State Determination using EQ. 3
Connection (S)(M) L Load State 170a 9,6 MBps 7 MBps Not congested
170b 9.6 MBps 7 MBps Not congested 170c 9,6 MBps 9 MBps Not
congested 170d 9.6 MBps 10 MBps Congested
[0052] Thus, table 2 illustrates an example scenario in which
connection 170d is determined to be congested as a result of the
fact that its traffic load exceeds 80% of its maximum permitted
load. Operating with a load above (S)(M) could, for example,
increase latency and/or the likelihood of dropped packets, which
may negatively impact the experience of mobile device users.
[0053] FIGS. 2A and 2B illustrate reconfiguration of a cell
boundary in response to one backhaul connection becoming
more-heavily loaded than another. In FIG. 2A, there is shown the
base station 102a, the base station 102b, a coverage area 204a of
the base station 102a, a coverage area 204b of the base station
102b, and mobile devices 202a and 202b.
[0054] Each of the mobile devices 202a and 202b may comprise
circuitry operable to communicate utilizing one or more wireless
protocols (e.g., LTE protocols). Each of the mobile devices 202a
and 202b may be, for example, a cellphone, a tablet computer, or a
laptop computer.
[0055] In FIG. 2A, the base station 102a is serving mobile device
202a via a wireless connection 210 and serving mobile device 202b
via a wireless connection 212. For illustration, assume that
connection 104a to the base station 102a is more heavily loaded, as
a result of the traffic to and/or from the mobile devices 202a and
202b and/or other traffic from non-base station devices on the
connection 104a, than the connection 104b serving base station
102b. The base station manager 114 may detect that the imbalance in
the traffic loads on connections 104a and 104b. FIG. 2B illustrates
an example response of the network manager to the detected
imbalance in the traffic loads on the connections 104a and 104b.
Specifically, FIG. 2B illustrates a response in which the base
station manager 114 reconfigures one or more parameter values to
cause the coverage areas 204a and 204b to be altered.
[0056] In an example implementation, the imbalance in traffic loads
may need to be greater than a threshold, I.sub.TH, before the base
station manager 114 detects the imbalance and/or determines to take
action to correct the imbalance. Additionally and/or alternatively,
temporal hysteresis may be utilized to prevent oscillations and/or
rapid changes in network configuration. The threshold may be
predetermined and/or determined real-time by the network manager
114. The threshold may be determined based, for example, on
historical data consumption patterns in the network.
[0057] Moving from FIG. 2A to FIG. 2B, the reconfiguring results in
the mobile device 202b being handed-over to the base station 102b
such that the mobile device 202b is now serviced via the connection
214 to base station 102b. After the handover, traffic to and from
the mobile device 202b is backhauled over connection 104b rather
than connection 104a, resulting in the total traffic load being
more-evenly distributed across connections 104a and 104b.
[0058] FIGS. 3A and 3B illustrate an example configuration and
reconfiguration of parameter values for traffic load distribution
in a network of small-cell base stations. In FIG. 3A, there is
shown the base station 102a and its coverage area 204a, the base
station 102b and its coverage area 204b, and mobile devices
202a-202e.
[0059] Each of the mobile devices 202a-202e may comprise circuitry
operable to communicate utilizing one or more wireless protocols
(e.g., LTE protocols). Each of the mobile devices 202a-202e may be,
for example, a cellphone, a tablet computer, or a laptop
computer.
[0060] In FIG. 3A, the base station 102a is serving mobile device
202a via a fireless connection 310 and base station 102b is serving
mobile devices 202b-202e via connections 314, 316, 318, and 320,
respectively. For illustration, assume that connection 104a (see
FIG. 1A) to the base station 102a is more heavily loaded, as a
result of the traffic to and/or from mobile device 202a and other
traffic from non-base station devices on the connection 104a, than
the connection 104b (see FIG. 1A) serving base station 102b (e.g.,
because connection 104b is not carrying a high amount of traffic
from non-base station devices). The base station manager 114 may
detect the imbalance in the traffic loads on connections 104a and
104b. FIG. 3A illustrates an example response of the network
manager to these detected conditions. Specifically, FIG. 3A
illustrates a response in which the base station manager 114
configures one or more parameter values of the base station 102a
such that association of the mobile device 202b with the base
station 102a is prevented (e.g., a request 312 from mobile device
202b may be dropped and/or responded-to with a denial) because
allowing the handover would only exacerbate the load imbalance.
[0061] Moving from FIG. 3A to FIG. 3B, assume now that the
connection 104b has now become more heavily loaded than connection
104a. The base station manager 114 may detect this imbalance. FIG.
3B illustrates an example response of the network manager to these
detected conditions. Specifically, FIG. 3B illustrates a response
in which the base station manager 114 configures one or more
parameter values of the base station 102a such that the base
station 102a is configured to accept handovers from base station
102b, and may configure one or more parameters of the base station
102a and/or 102b such that handover occurs. For example, a transmit
power utilized for the connection 314 may be reduced such that the
mobile device 202b determines that associating with the base
station 102a will provide better performance.
[0062] In an example implementation, the parameters associated with
connection 314 may be configured without affecting the connections
316, 318, and 320. For example, transmit power may only be
decreased for a channel (e.g., frequency, timeslot, and/or CDMA
code) associated with the connection 314 while transmit power for
channel(s) associated with the connections 316, 318, and 320 may
remain the same,
[0063] FIG. 4 illustrates a cyclical handing over of a mobile
device for traffic load distribution among a plurality of backhaul
connections. Shown in FIG. 4, are three network states 402, 412,
and 422, which differ in the base station that service mobile
device 202a. The data consumption of the mobile device 202a (and
other devices in the network not shown in FIG. 4) may be such that
whichever backhaut connection handles traffic for mobile device
202a, that backhaut connection is going to be more heavily loaded
than the other two backhaul connections. Accordingly, the network
manager 114 may cause the mobile device 202a to be cyclically
handed-over among the three base stations 102a, 102b, and 102c
(i.e., from base station 102a (state 204), to base station 102b
(state 412), to base station 102c (state 422), back to state 102a,
and so on). The amount of time spent in each of the three states
may be predetermined and/or determined in real-time by the network
manager 114. The amount of time may be determined based, for
example, on historical data consumption patterns in the network.
Where, there are only two base stations, cyclical handing over
equates to repeated hand-offs back and forth between the two base
stations.
[0064] FIG. 5 illustrates communication of network management
messages for managing traffic loads backhaul connections of
small-cell base stations. Again shown in FIG. 5 is the network 100
shown in FIG. 1. Also shown are various paths via which network
management messages 602 may be communicated. The paths shown in
FIG. 5 are merely examples of paths via which various devices of
the network 100 may interface with one another. Any one or more of
the paths shown in FIG. 5 may not be present in a particular
embodiment. In a particular embodiment, any one or more of the
paths shown as wired may additionally or alternatively comprise
wired and/or optical links. In a particular embodiment, any one or
more of the paths shown as wireless may additionally or
alternatively comprise wireless and/or optical links.
[0065] The path 602 is a wired, wireless, and/or optical path
between the network manager 114 and the base station 102b, The path
602 may comprise one or more hops and includes the backhaul
connection 104b. The path 604 is a wireless path between the base
station manager 114 and the base station 102a. The path 604 is thus
out-of-band with the backhaul connection 104a that serves base
station 102a. The path 606 is a wireless path between base stations
102a and 102b. The path 608 is a wireless path between the base
station 102b and the mobile device 202a. The path 610 is a wireless
path between the mobile device 202a and the base station 102a.
Messages sent over the path 608 may be forwarded onto the path 610.
The path 612 is a wired, wireless, and/or optical path between base
stations 102a and 102b. The path 612 may comprise one or more hops
and includes the backhaul connections 104a and 104b.
[0066] FIG. 6 is a flowchart illustrating steps for load
distribution in a network of small-cell base stations. In step 604,
after start step 602, the base station manager 114 may collect
information about one or more connections which serve as backhaul
connections for one or more small-cell base stations. The collected
information may include the information depicted in FIG. 1D and/or
may include other information. The information may, for example, be
collected via a series of queries and responses sent by the base
station manager 114 to other devices in the network and
corresponding responses received by the base station manger 114
from the queried devices. In step 606, the collected information
may be utilized to determine whether there is a significant (e.g.,
greater than a threshold amount) imbalance in the loads carried by
one or more backhaul connections of the network. The determination
in step 606 may, for example, be made utilizing equations 1, 2, 3,
and/or 4 described above. If a significant imbalance is detected;
then in step 608, one or more parameter values may be configured
to, for example, reduce a load on heavily-loaded connection(s),
shift traffic from heavily-loaded connection(s) to lightly-loaded
connection(s), and/or prevent the imbalance from worsening (e.g.,
prevent new cellular connections that will be backhauled over the
heavily loaded connection(s)). Returning to step 606, if there is
not a significant imbalance, the steps may advance to step 610 and
a current configuration of the network may be maintained.
[0067] Other implementations may provide a non-transitory computer
readable medium and/or storage medium, and/or a non-transitory
machine readable medium and/or storage medium, having stored
thereon; a machine code and/or a computer program having at least
one code section executable by a machine and/or a computer, thereby
causing the machine and/or computer to perform the steps as
described herein for load distribution in a network of small-cell
base stations.
[0068] Accordingly, the present method and/or apparatus may be
realized in hardware, software, or a combination of hardware and
software. The present method and/or apparatus may be realized in a
centralized fashion in at least one computing system, or in a
distributed fashion where different elements are spread across
several interconnected computing systems. Any kind of computing
system or other apparatus adapted for carrying out the methods
described herein is suited. Atypical combination of hardware and
software may be a general-purpose computing system with a program
or other code that, when being loaded and executed, controls the
computing system such that it carries out the methods described
herein. Another typical implementation may comprise an application
specific integrated circuit or chip.
[0069] The present method and/or apparatus may also be embedded in
a computer program product, which comprises all the features
enabling the implementation of the methods described herein, and
which when loaded in a computer system is able to carry out these
methods. Computer program in the present context means any
expression, in any language, code or notation, of a set of
instructions intended to cause a system having an information
processing capability to perform a particular function either
directly or after either or both of the following: a) conversion to
another language, code or notation; b) reproduction in a different
material form.
[0070] While the present method and/or apparatus has been described
with reference to certain implementations, it will be understood by
those skilled in the art that various changes may be made and
equivalents may be substituted without departing from the scope of
the present method and/or apparatus. In addition, many
modifications may be made to adapt a particular situation or
material to the teachings of the present disclosure without
departing from its scope. Therefore, it is intended that the
present method and/or apparatus not be limited to the particular
implementations disclosed, but that the present method and/or
apparatus will include all implementations fatting within the scope
of the appended claims.
[0071] A number of implementations have been described.
Nevertheless, it will be understood that various modifications may
be made without departing from the spirit and scope of the
disclosure. Accordingly, other implementations are within the scope
of the following claims.
* * * * *