U.S. patent application number 12/580604 was filed with the patent office on 2011-04-21 for self-optimizing wireless network.
Invention is credited to Osama Hussein, Hafedh Trigui.
Application Number | 20110090820 12/580604 |
Document ID | / |
Family ID | 43876434 |
Filed Date | 2011-04-21 |
United States Patent
Application |
20110090820 |
Kind Code |
A1 |
Hussein; Osama ; et
al. |
April 21, 2011 |
SELF-OPTIMIZING WIRELESS NETWORK
Abstract
Optimizing a plurality cell sites or sectors in a wireless
network including receiving network data regarding a plurality of
cell sites or sectors; determining a critical zone in which
communication is degraded; determining best neighbor cell sites or
sectors among the neighbor cell sites or sectors associated with
the critical cell sites or sectors; determining if the critical
cell sites or sectors in the critical zone have available resources
for achieving a desired improvement in communications; determining
if the best neighbor cell sites or sectors have available resources
for achieving the desired improvement in communications; and
altering wireless network parameters of the critical cell sites or
sectors, or the best neighbor cells sites or sectors for achieving
the desired improvement in communications. Altering wireless
network parameters of the critical cell sites or sectors, or the
best neighbor cell sites or sectors is performed continuously until
the desired improvement in communications in the wireless network
is achieved.
Inventors: |
Hussein; Osama; (Leesburg,
VA) ; Trigui; Hafedh; (Ottawa, CA) |
Family ID: |
43876434 |
Appl. No.: |
12/580604 |
Filed: |
October 16, 2009 |
Current U.S.
Class: |
370/255 |
Current CPC
Class: |
H04W 24/02 20130101;
H04W 16/18 20130101; H04W 72/04 20130101 |
Class at
Publication: |
370/255 |
International
Class: |
H04L 12/28 20060101
H04L012/28 |
Claims
1. A method for optimizing a plurality cell sites or sectors in a
wireless network, the method comprising: receiving network data
regarding a plurality of cell sites or sectors, each cell site or
sector corresponding to a coverage area for providing
communications in a wireless network; evaluating the network data
to determine if communications provided by the plurality of cell
sites or sectors has been degraded; determining a critical zone in
which communication is degraded, the critical zone including
critical cell sites or sectors needing improved communications and
neighbor cell sites or sectors corresponding to the critical cell
sites or sectors; determining best neighbor cell sites or sectors
among the neighbor cell sites or sectors associated with the
critical cell sites or sectors; determining if the critical cell
sites or sectors in the critical zone have available resources for
achieving a desired improvement in communications; determining if
the best neighbor cell sites or sectors have available resources
for achieving the desired improvement in communications, when it is
determined that the critical cells sites or sectors do not have
adequate available resources for achieving the desired improvements
in communications; altering wireless network parameters of the
critical cell sites or sectors, or of the best neighbor cells sites
or sectors for achieving the desired improvement in communications;
and determining if the desired improvement in communications has
been achieved by altering the wireless network parameters, wherein
altering wireless network parameters of the critical cell sites or
sectors, or the best neighbor cell sites or sectors is performed
continuously until the desired improvement in communications in the
wireless network is achieved.
2. The method for optimizing of claim 1, further comprising:
determining a critical hour within the critical zone at which the
degraded communications occurs; determining if the critical cell
sites or sectors in the critical zone have available resources at
the critical hour for achieving the desired improvement in
communications; and determining if the best neighbor cell sites or
sectors have available resources at the critical hour for achieving
the desired improvement in communications, when it is determined
that the critical cells sites or sectors do not have adequate
available resources at the critical hour for achieving the desired
improvements in communication.
3. The method for optimizing of claim 1, wherein determining if
there is an improvement in communications based on the altered
wireless network parameters of the critical cell site or sector, or
the best neighbor cells sites or sectors is based on monitoring
network data during a specified time period or observation
window.
4. The method for optimizing of claim 1, wherein the at least one
network parameters includes a horizontal and vertical pointing
direction of at least one controllable antenna, beamwidth of the at
least one controllable antenna, or a transmit power of at least one
base station.
5. The method for optimizing of claim 1, wherein the desired
improvement in communications in the wireless network is determined
based on key performance indicators (KPIs).
6. The method for optimizing of claim 1, wherein determining the
critical zone further comprises: identifying a critical cell site
or sector needing improved communications by a reference_ID;
creating a cell table by collecting a list of neighbor cell sites
or sectors corresponding to the critical cell site or sector;
sorting cell table by zone_IDs and then by cell_IDs; determining if
the reference_ID matches a cell_ID stored in the cell table, and if
so designate cell_ID as X; determining if the reference_ID matches
a zone_ID stored in the cell table, and if so designate zone_ID as
Y; determining if X and Y are included in the critical zone, such
that: if X is included in the critical zone and Y is not, add Y to
the critical zone. if Y is included in the critical zone and X is
not, then add X to the critical zone, if neither X and Y are not
included in the critical zone, then create a new critical zone
including X and Y, and if X and Y are included in two different
critical zones, then create a new critical zone including X and Y,
wherein the determination of a critical zone is performed
continuously for all cells sites or sectors in the wireless
network.
7. The method for optimizing of claim 1, wherein finding the best
neighbor cell sites or sectors includes: sorting neighbor cell
sites or sectors based on network statistics; grouping neighbor
cell sites or sectors into a plurality of groups and an order of
the plurality of groups based on resources available and network
statistics; ranking the neighbor cell sites or sectors in each
group based on resources available and network statistics;
determining a best neighbor cell site or sector in a group, and if
the best neighbor cell site or sector is not determined, searching
a next group for the best neighbor cell site or sector; determining
if the best neighbor cell site or sector has sufficient resources
for improving communications; and calculating alterations or
modifications needed to neighbor cell site or sector for improving
communications.
8. A program recorded on a computer-readable storage medium for
optimizing a plurality cell sites or sectors in a wireless network,
the program causing a computer to execute optimizing steps
comprising: receiving network data regarding a plurality of cell
sites or sectors, each cell site or sector corresponding to a
coverage area for providing communications in a wireless network;
evaluating the network data to determine if communications provided
by the plurality of cell sites or sectors has been degraded;
determining a critical zone in which communication is degraded, the
critical zone including critical cell sites or sectors needing
improved communications and neighbor cell sites or sectors
corresponding to the critical cell sites or sectors; determining
best neighbor cell sites or sectors among the neighbor cell sites
or sectors associated with the critical cell sites or sectors;
determining if the critical cell sites or sectors in the critical
zone have available resources for achieving a desired improvement
in communications; determining if the best neighbor cell sites or
sectors have available resources for achieving the desired
improvement in communications, when it is determined that the
critical cells sites or sectors do not have adequate available
resources for achieving the desired improvements in communications;
altering wireless network parameters of the critical cell sites or
sectors, or the best neighbor cells sites or sectors for achieving
the desired improvement in communications; and determining if the
desired improvement in communications has been achieved by altering
the wireless network parameters, wherein altering wireless network
parameters of the critical cell sites or sectors, or the best
neighbor cell sites or sectors is performed continuously until the
desired improvement in communications in the wireless network is
achieved.
9. The program for optimizing of claim 8, further comprising:
determining a critical hour within the critical zone at which the
degraded communications occurs; determining if the critical cell
sites or sectors in the critical zone have available resources at
the critical hour for achieving the desired improvement in
communications; and determining if the best neighbor cell sites or
sectors have available resources at the critical hour for achieving
the desired improvement in communications, when it is determined
that the critical cells sites or sectors do not have adequate
available resources at the critical hour for achieving the desired
improvements in communication.
10. The program for optimizing of claim 8, wherein determining if
there is an improvement in communications based on the altered
wireless network parameters of the critical cell site or sectors,
or the best neighbor cells sites or sectors based on monitoring
network data during a specified time period or observation
window.
11. The program for optimizing of claim 8, wherein the at least one
network parameters include a horizontal and vertical pointing
direction of at least one controllable antenna, beamwidth of the at
least one controllable antenna, or a transmit power of at least one
base station.
12. The program for optimizing of claim 8, wherein the desired
improvement in communications in the wireless network is determined
based on key performance indicators (KPIs).
13. The program for optimizing of claim 8, wherein determining the
critical zone further comprises: identifying a critical cell site
or sector needing improved communications by a reference_ID;
creating a cell table by collecting a list of neighbor cell sites
or sectors corresponding to the critical cell site or sector;
sorting cell table by zone_IDs and then by cell_IDs; determining if
the reference_ID matches a cell_ID stored in the cell table, and if
so designate cell_ID as X; determining if the reference_ID matches
a zone_ID stored in the cell table, and if so designate zone_ID as
Y; determining if X and Y are included in the critical zone, such
that: if X is included in the critical zone and Y is not, add Y to
the critical zone, if Y is included in the critical zone and X is
not, then add X to the critical zone, if neither X and Y are not
included in the critical zone, then create a new critical zone
including X and Y, and if X and Y are included in two different
critical zones, then create a new critical zone including X and Y,
wherein the determination of a critical zone is performed
continuously for all cells sites or sector in the wireless
network.
14. The program for optimizing of claim 8, wherein finding the best
neighbor cell sites or sectors includes: sorting neighbor cell
sites or sectors based on network statistics; grouping neighbor
cell sites or sectors into a plurality of groups and determining an
order of the plurality of groups based on resources available and
network statistics; ranking neighbor cell sites or sectors in each
or the groups based on resources available and network statistics;
determining a best neighbor cell site or sector in a group, and if
the best neighbor cell site or sector is not determined, searching
a next group for the best neighbor cell site or sector; determining
if best neighbor cell site or sector has sufficient resources for
improving communications; and calculating alterations or
modifications needed to neighbor cell site or sector for improving
communications.
15. A system for optimizing a plurality cell sites in a wireless
network, the system comprising: an optimization apparatus that
monitors network data associated with a plurality of cell sites or
sectors and performs alterations to network parameters wireless
network; at least one controller configured to perform data
communications with said optimization apparatus; a least one base
station configured to perform data communication with said at least
one controller; at least one controllable antenna configured to
perform data communication with said at least one base station and
a plurality of subscribers distributed in a plurality of coverage
areas; and a dynamic load balancing apparatus configured to perform
data communication with said optimization apparatus and said at
least one controllable antenna, said optimization apparatus being
configured to: receive network data regarding the plurality of cell
sites or sectors, each cell site or sector corresponding to a
coverage area for providing communications in a wireless network;
evaluate the network data to determine if communications provided
by the plurality of cell sites or sectors has been degraded;
determine a critical zone in which communication is degraded, the
critical zone including critical cell sites or sectors needing
improved communications and neighbor cell sites or sectors
corresponding to the critical cell sites or sectors; determine best
neighbor cell sites or sectors among the neighbor cell sites or
sectors associated with the critical cell sites or sectors;
determine if the critical cell sites or sectors in the critical
zone have available resources for achieving a desired improvement
in communications; determine if the best neighbor cell sites or
sectors have available resources for achieving the desired
improvement in communications, when it is determined that the
critical cells sites or sectors do not have adequate available
resources for achieving the desired improvements in communications;
alter wireless network parameters of the critical cell sites or
sectors, or the best neighbor cells sites or sectors for achieving
the desired improvement in communications; and determine if the
desired improvement in communications has been achieved by altering
the wireless network parameters, wherein altering wireless network
parameters of the critical cell sites or sectors, or the best
neighbor cell sites or sectors is performed continuously until the
desired improvement in communications in the wireless network is
achieved.
16. The system for optimizing of claim 15, further comprising a
network database configured to store the target criteria, network
topology and parameters, and network statistics regarding the
wireless network.
17. An apparatus for optimizing a plurality cell sites in a
wireless network, the apparatus comprising: a communication
interface; at least one processor; and a memory, the memory storing
an optimizing program for causing the apparatus to perform
optimizing steps comprising: receiving network data regarding a
plurality of cell sites or sectors, each cell site or sector
corresponding to a coverage area for providing communications in a
wireless network; evaluating the network data to determine if
communications provided by the plurality of cell sites or sectors
has been degraded; determining a critical zone in which
communication is degraded, the critical zone including critical
cell sites or sectors needing improved communications and neighbor
cell sites or sectors corresponding to the critical cell sites or
sectors; determining best neighbor cell sites or sectors among the
neighbor cell sites or sectors associated with the critical cell
sites or sectors; determining if the critical cell sites or sectors
in the critical zone have available resources for achieving a
desired improvement in communications; determining if the best
neighbor cell sites or sectors have available resources for
achieving the desired improvement in communications, when it is
determined that the critical cells sites or sectors do not have
adequate available resources for achieving the desired improvements
in communications; altering wireless network parameters of the
critical cell sites or sectors, or the best neighbor cells sites or
sectors for achieving the desired improvement in communications;
and determining if the desired improvement in communications has
been achieved by altering the wireless network parameters, wherein
altering wireless network parameters of the critical cell sites or
sectors, or the best neighbor cell sites or sectors is performed
continuously until the desired improvement in communications in the
wireless network is achieved.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to planning and
optimization for a wireless network. In particular, the present
invention relates to a system that monitors network performance,
and makes changes to network parameters to enhance performance.
[0003] 2. Description of the Related Art
[0004] Network planning of a wireless network relies on static
approaches for site locations and dimensioning of the radio
resources to meet specified traffic demand at busy hours. In a
wireless network, a large number of base stations (i.e., cell
sites) can be served by one or more antennas. The base station
hardware will send a radio frequency signal to the antennas, which
will typically be placed on towers or buildings. Each antenna
(i.e., sector) serves end-users located in a coverage area. Within
a coverage area different types of services can be provided (e.g.,
voice and data services).
[0005] The coverage area provided by an antenna is determined by
antenna configurations and input power to the antenna. Antenna
configurations are, for example, the antenna horizontal pointing
direction, the azimuth beamwidth of the antenna, and downtilt angle
of the antenna. Modifying these antenna configurations will change
the area the antenna is serving (i.e., coverage area) and possibly
areas served by other surrounding antennas.
[0006] Input power (i.e., the power sent from the base station or
cell site) to the antenna will also affect the coverage of the
antenna as well as the interference that impacts the coverage areas
of neighboring antennas. For example, if an antenna's input power
is increased, the coverage area of the antenna may increase as
well, thereby causing interference to the coverage area of a
neighboring antenna and affecting the quality of service in that
neighboring antenna's coverage area. When the radio signal quality
is better, due to good network planning and performance, higher
data rates for voice and data services can be achieved without
consuming too many radio power resources.
[0007] Network planning and optimization is a process of finding
the best configuration of the wireless network so as to maximize
performance of the network. This process typically starts with an
already working wireless network, and then calculations and
analysis are done by engineers using software and hardware tools
and extensive simulations for the network. Once a better
configuration is determined, the new configuration will be manually
implemented in the network.
[0008] However, network planning and optimization consumes a high
amount of human resources. In addition, it is a lengthy process
which is done only when needed or periodically with long periods
between implementation. In addition, because this process is manual
and lengthy, it is conducted with low frequency, which results in
leaving the network or parts of the network without optimization
for long periods of time. Thus, network resource usage is not
maximized and unused available network resources result in
significant revenue loss. Finally, quality of service is degraded,
which affects the end user's overall customer satisfaction.
[0009] Therefore, it would be useful to implement an automated
system for network planning and optimization that adjusts radio
resources and network parameters to maximize overall network
performance.
SUMMARY OF THE INVENTION
[0010] An embodiment of the invention is directed to a method for
optimizing a plurality cell sites/sectors in a wireless network.
The method includes receiving network data regarding a plurality of
cell sites/sectors, each cell site/sector corresponding to a
coverage area for providing communications in a wireless network;
evaluating the network data to determine if communications provided
by the plurality of cell sites/sectors has been degraded; and
determining a critical zone in which communication is degraded. The
critical zone includes critical cell sites/sectors needing improved
communications and neighbor cell sites/sectors corresponding to the
critical cell sites/sectors.
[0011] The method also includes determining best neighbor cell
sites/sectors among the neighbor cell sites/sectors; determining if
the critical cell sites/sectors in the critical zone have available
resources for achieving a desired improvement in communications;
determining if the best neighbor cell sites/sectors have available
resources for achieving the desired improvement in communications,
when it is determined that the critical cells sites do not have
adequate available resources for achieving the desired improvements
in communications; altering wireless network parameters of the
critical cell sites/sectors or the best neighbor cells sites for
achieving the desired improvement in communications; and
determining if the desired improvement in communications has been
achieved by altering the wireless network parameters.
[0012] Altering wireless network parameters of the critical cell
sites/sectors or the best neighbor cell sites/sectors are performed
continuously until the desired improvement in communications in the
wireless network is achieved.
[0013] An embodiment of the invention is also directed to program
recorded on a computer-readable storage medium for optimizing a
plurality cell sites/sectors in a wireless network. The program
causes a computer to execute optimizing steps comprising receiving
network data regarding a plurality of cell sites/sectors;
evaluating the network data to determine if communications provided
by the plurality of cell sites/sectors has been degraded; and
determining a critical zone in which communication is degraded.
[0014] The program also causes the computer to perform the steps of
determining best neighbor cell sites/sectors among the neighbor
cell sites/sectors; determining if the critical cell sites/sectors
have available resources for achieving a desired improvement in
communications; determining if the best neighbor cell sites/sectors
have available resources for achieving the desired improvement in
communications, when it is determined that the critical cells sites
do not have adequate available resources; altering wireless network
parameters of the critical cell sites/sectors or the best neighbor
cells sites for achieving the desired improvement in
communications; and determining if the desired improvement in
communications has been achieved by altering the wireless network
parameters.
[0015] An embodiment of the invention is also directed to a system
for optimizing a plurality cell sites/sectors in a wireless
network. The system comprising an optimization apparatus that
monitors network data associated with a plurality of cell
sites/sectors and performs alterations to network parameters
wireless network; at least one controller configured to perform
data communications with the optimization apparatus; a least one
base station configured to perform data communication with the at
least one controller; at least one controllable antenna configured
to perform data communication with the at least one base station
and a plurality of subscribers distributed in a plurality of
coverage areas; and a dynamic load balancing apparatus configured
to perform data communication with the optimization apparatus and
the at least one controllable antenna.
[0016] An embodiment of the invention is also directed an apparatus
for optimizing a plurality cell sites/sectors in a wireless network
comprises a communication interface; at least one processor; and a
memory, the memory storing a optimizing program for causing the
apparatus to perform optimizing operations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In the drawings, like reference numbers generally indicate
identical, functionally similar and/or structurally similar
elements. Embodiments of the invention will be described with
reference to the accompanying drawings, wherein:
[0018] FIG. 1 illustrates a system for optimizing of network
parameters in a wireless network in accordance with an embodiment
of the invention;
[0019] FIG. 2 illustrates a method for optimizing of network
parameters in a wireless network in accordance with an embodiment
of the invention;
[0020] FIG. 3 illustrates a method for determining a critical zone
requiring optimizing of network parameters in accordance with an
embodiment of the invention;
[0021] FIG. 4 illustrates a method for determining a best neighbor
cell in accordance with an embodiment of the invention; and
[0022] FIG. 5 illustrates an apparatus for optimizing of network
parameters in a wireless network in accordance with an embodiment
of the invention.
[0023] Additional features are described herein, and will be
apparent from the following description of the figures.
DETAILED DESCRIPTION OF THE INVENTION
[0024] In the description that follows, numerous details are set
forth in order to provide a thorough understanding of the
invention. It will be appreciated by those skilled in the art that
variations of these specific details are possible while still
achieving the results of the invention. Well-known elements and
processing steps are generally not described in detail in order to
avoid unnecessarily obscuring the description of the invention.
[0025] In the drawings accompanying the description that follows,
often both reference numerals and legends (labels, text
descriptions) may be used to identify elements. If legends are
provided, they are intended merely as an aid to the reader, and
should not in any way be interpreted as limiting.
[0026] FIG. 1 is a system for optimizing of network parameters in a
wireless network in accordance with an embodiment of the invention.
In particular, the wireless network 100 illustrated in FIG. 1
includes a network optimization apparatus 101. The wireless network
100 refers to any type of computer network that is wireless, and is
commonly associated with a telecommunications network whose
interconnections are implemented without the use of wires such as
with electromagnetic waves, such as radio waves or the like as a
carrier. The basic components of the wireless network 100 include
the network optimization apparatus 101, one or more controllers
102, and one or more base stations 103 (i.e., cell sites) for
supporting data communications between subscribers distributed
throughout coverage areas provided by the wireless network 100 via
antennas 105 (i.e., sectors), a network database 110, and a dynamic
load balancing apparatus 104.
[0027] It should be understood by one of ordinary skill in the art
that the connections between the network optimization apparatus 101
and the one or more network controllers 102, the dynamic load
balancing apparatus 104 and the network database 110 can be
wireless, wired or a combination of wireless and wired. Similarly,
it should be understood by one of ordinary skill in the art that
the connections between the one or more controllers 102 and the one
or more base stations 103 can be wireless, wired or a combination
of wireless and wired.
[0028] As seen in FIG. 1, the network optimization apparatus 101
receives network statistics and the current network configurations
from the network database 110 related to the wireless communication
system 100 for assisting in the monitoring and optimization
performed. The network statistics may include, but are not limited
to, key performance Indicators (KPIs). An example of a KPI is the
dropped calls rate, which is the ratio between the failed calls and
the total number of calls requested. Another network statistic is
the capacity of the network. Capacity can be measured by total
number of calls and/or the amount of delivered data in bits or the
throughput (overall data rate) in case of data calls.
[0029] A network parameter important to consider when performing
network optimization is the number of handovers of end-user
equipments between different sectors. User equipment has serving
sectors, as the user moves between the coverage areas of different
sectors, the serving sector will be changed as other sectors may
have better signal quality. In a soft handover, the user will have
more than one serving sector in the same time as the signal quality
of different sectors are close to each other. The number of
handovers between different sectors could be used as indicator of
how close sectors are to each other, or an indicator to the
dependency between different sectors.
[0030] Another network parameter important to consider when
performing network optimization is a neighbor list. The neighbor
list includes all the potential neighbors for a sector, and it may
include neighbor priorities as well. A potential neighbor is a
neighbor sector which may provided services to mobile equipment as
part of a handover operation when the mobile equipment is traveling
between different coverage areas. The neighbor lists of the sectors
which are serving the mobile equipment may be arranged to construct
one list to be sent to the mobile equipment. The mobile equipment
will use this longer list to search for additional potential
neighbors for handover operations.
[0031] The network optimization apparatus 101 can be a server or
other similar computer device capable of executing an algorithm for
performing optimization of network parameters in wireless network
100. A more detailed discussion of the structure of the network
optimization apparatus 101 is noted below with reference to FIG.
5.
[0032] The controllers 102 illustrated in FIG. 1 are, for example,
base station controllers (BSC), which are part of the wireless
system infrastructure that control one or more of the base stations
103 and the corresponding coverage areas provided by the base
stations 103. A plurality of subscribers (not shown) is distributed
within the coverage areas for participating in wireless data
communications provided by the wireless network 100 via the
antennas 105. The subscribers have user equipment that may include
various types of fixed, mobile, and portable two way radios,
cellular telephones, personal digital assistants (PDAs), or other
wireless networking devices.
[0033] Each coverage area behaves as an independent sector serving
its own set of subscribers. For fixed wireless systems, such as
IEEE802.16-2004, each coverage area can be used by a single base
station 103 or plurality of base stations 103 operating each on a
different frequency channel. For mobile systems, subscribers of a
single coverage area are served by a single base station 103 that
can be a single frequency channel for IEEE802.16e-2005 (or UMTS or
1x-EVDO Rev. B and C) or multiple frequency channels that can be
supported by IEEE802.16m (or UMTS or 1xEVDO Rev. B and C).
[0034] As illustrated in FIG. 1, the dynamic load balancing
apparatus 104 may also receive subscriber statistics. The dynamic
load balancing apparatus 104 includes an algorithm that analyzes
the data related to the wireless network 100 and sends control
signals to the antennas and/or base stations 103 for altering or
shaping the coverage areas. The load balancing algorithm may
cluster users based on their instantaneous locations or by means of
heuristic approaches; collects statistics to validate previous
users clustering decisions and/or predicting new traffic patterns;
and continuous learns and adaptively shapes the coverage areas and
alters network parameters as the environment or traffic density
changes with time. As seen in FIG. 1, network statistics received
by the network optimization apparatus can also be provided to the
dynamic load balancing apparatus 104.
[0035] FIG. 2 illustrates a method for optimizing of network
parameters in a wireless network in accordance with an embodiment
of the invention. By way of example, the self-optimization
apparatus 101 can execute an algorithm stored therein for
performing optimization operations.
[0036] Prior to optimizing operations on the wireless network,
there needs to be an identification of zones (i.e., critical zones)
in the wireless network requiring optimization. Identification of a
critical zone will be discussed in more detail with reference to
FIG. 3. The zones will be identified as a group of cell
sites/sectors on which the optimization will be preformed.
Identification of the zones needing optimization can be based on
the critical cell site/sector that has performance problems based
on some criteria. Additionally, different areas of the wireless
network can be evaluated using different criteria. The criteria can
be based on one or more performance metrics of the wireless network
over a past period of time and/or one or more predicted performance
metrics. These performance metrics can be based on previous
performance and configurations as well as previous traffic and
predicted traffic.
[0037] A performance metrics can be for a voice/data service for
all services or for weighted services; and can be for the critical
cell site/sector only or for the entire critical zone or for
overall weighted performance between different cell sites/sectors.
The performance metrics can also be for a specific time slot in a
day or over a few days, for all times or for overall weighted
times, and can be changed automatically or manually between
different sets of performance metrics based on some criteria. For
the criteria that changes automatically between different
performance metrics sets, the criteria can be based on past or
predicted configurations, performance metrics and/or traffic.
[0038] For each critical cell site/sector needing optimization, a
local zone will be identified as the set of the neighbor cell
sites/sectors based on some criteria, which can also be based on
one or more performance metrics. For example, the performance
metric can be based on the cells/sectors dropped call rate (DCR),
which has exceeded certain dropped call rate threshold over certain
window of time. The performance metric can also be calculated
across specific time slots in different time frames. For example,
Mondays to Fridays, Mondays only or Mondays to Fridays morning
hours.
[0039] The local zone may contain only the critical cell/sector,
direct neighbors of the critical site/sector or the direct
neighbors and the neighbors of neighbors or additional levels of
neighbors. For each group of overlapped local zones, critical zones
will be identified as the union of these overlapped zones. The
final critical zones may not include overlapping zones. The zone
identification process is run continuously to identify new zones
needing optimization.
[0040] The old and newly identified critical zones can also be
ranked based on the criteria used in identifying the critical
zones. Based on the available computing resource in the
optimization system as well as the rank of the zones, one or more
of the critical zones will be chosen for optimization in serial,
parallel or both. When a critical zone is selected for
optimization, the optimization will be conducted continuously as
performance metric data and configurations arrive to the
optimization apparatus, as shown in FIG. 2.
[0041] Referring now to FIG. 2, in step 201, the self-optimization
apparatus 101 monitors the wireless network. The self-optimization
apparatus 101 monitors performance after implementing recommended
configuration modifications. In step 202, the network optimization
apparatus 101 determines if new network data has been received. If
not, then the wireless network will continue to be monitored, as in
step 201. Otherwise, in step 203, the network optimization
apparatus 101 will determine whether the operating conditions of
the cell sites/sectors in the zones have been degraded based on the
new data received. The criteria can be based on one or more of
performance metrics similar to those noted above for identifying
the zones. For example, the performance metric can be based on the
DCR of cells/sectors in the zones or capacity increases. If
performance in the zone has degraded, then in step 204, the
previous recommended configuration modifications are removed until
the best previous operation state is achieved, and in step 220 the
self-optimization process ends.
[0042] However, if the operating conditions of the zones have not
been degraded based on the previous recommended configuration
modifications, then in step 205 it is determined if an observation
window has been reached. An observation window is simply a
specified time period such a number or days. For example, the
optimization apparatus may determine that it is necessary to
monitor network data for a certain numbers of days. If an
observation window has not been reached, then the wireless network
will continue to be monitored, as in step 201. However, once the
observation window has been reached, performance metrics can be
calculated and compared to performance metrics before the previous
recommended configuration modifications or compared to the first
KPIs. An algorithm will evaluate the KPIs after the previous
observation windows have been reached and find the configurations
which resulted in the best KPIs. If the current network performance
is better, then the previous recommended configuration
modifications will be accepted. However, if performance is
degraded, then the previous recommended configuration modifications
are removed.
[0043] Thus, after the observation window has been reached in step
205 then, in step 206 it is determined if the operating conditions
of the cell sites/sectors in the zones have been degraded. If a
degraded condition is determined in step 206, then in step 204 the
previous recommended configuration modifications are removed until
the best previous operation state is achieved, and in step 220 the
self-optimization process ends. If in step 206 it is determined
that the operating conditions of the cell sites/sectors in the
zones have not been degraded, then in step 207 a critical hour is
determined.
[0044] The critical hour may be the specific time a zone suffers
from a highly degraded condition. In step 208, it is determined if
the critical cell/sector has enough available resources for the
critical hour. For example, the determination of available
resources could be based on, but is not limited to, the number of
calls which could be additionally served by the critical cell
site/sector; how many calls could be averagely served by any used
hardware; or how many calls could be averagely served by the unused
power. If the number of calls is determined to be less or greater
than a preset/dynamic threshold, then it can be determined if the
critical cell site/sector has adequate available resources to
address the degraded condition.
[0045] If it is determined that the cell site/sector has available
resources, then the previous recommended configuration
modifications are removed (in step 204) and, for example, load
balancing techniques can be used to address the degradation
condition in the zone instead. The optimization process is then
ended in step 220. If the cell site/sector does not have adequate
available resources, then in step 209 a best neighbor cell
site/sector is determined for assisting in addressing the degraded
condition. For example, from the critical cell sectors/site
neighbor list, the top neighbors are determined based on which
neighbors sectors/sites have a high number of handovers with the
critical cell site/sector; and/or the neighbor cell sectors/cells
with antenna beams looking toward the critical site/sector; and/or
the neighbor cell sectors/sites which has high available
resources.
[0046] In step 210, if no best neighbor site is found, then the
previous recommended configuration modifications are removed in
step 204 and the optimization process is ended in step 220. In the
alternative, if no best neighbor is found using the current
criteria, then the search criteria for a best neighbor cell/sector
could be modified or made more flexible, for example, to determine
neighbor cells/sectors with a lower number of handovers. Found best
neighbor cells/sectors could be in the same cell site/sector
location or different location from the critical cell site/sector.
Additionally, there can be different priorities if the neighbor
cell sectors/sites are in different cell site/sector location than
for neighbor cell sectors/sites in same cell site/sector location.
These priorities can be specified using a weighted metrics and the
status of whether the neighbor cell sectors/sites is in the same or
different cell site/sector.
[0047] If a best neighbor site/or cell is found in step 210, then
in step 211 it is determined if the best neighbor cell has adequate
available resources for addressing the degraded condition. If the
best neighbor cell/sector does not have adequate available
resources, then the previous recommended configuration
modifications are removed in step 204 and the optimization process
is ended in step 220. If the best neighbor cell has adequate
available resources for addressing the degraded condition, then
configuration modifications are calculated and added to the
modification queue in step 212 for application to the wireless
network.
[0048] The calculated configuration modification could be that, for
example, the critical cell site/sector antenna down tilt will be
increased and/or the critical cell site/sector transmitted power
will be decreased; the critical cell site/sector antenna pointing
direction will be moved away from the neighbor which has more
available resources or away from a neighbor cell/sector which has
less available resources; and/or the critical cell site/sector
antenna beamwidth will be decreased; and/or the critical cell
site/sector transmitted power will be decreased to compensate for
the increase in gain cased by decreasing beamwidth.
[0049] Additionally the calculated configuration modification could
be that, for example, that the best neighbor cell site/sector
antenna down tilt will be decreased and/or the best neighbor cell
site/sector transmitted power will be increased; the best neighbor
cell site/sector antenna pointing direction will be moved towards
the critical cell site/sector; and/or the best neighbor cell
site/sector antenna beamwidth will be increased; and/or the best
neighbor cell site/sector transmitted power will be increased to
compensate for the decrease in gain cased by increasing beamwidth.
The recommendations above can be implemented simultaneously or
sequentially or with time delay in between or delayed until the
next window is reached or until all delayed recommendations are
implemented.
[0050] Once the recommendation modifications are determined, the
wireless network is monitored (as in step 201) to determine if the
recommendation modification address the degraded condition.
[0051] Exemplary Application
[0052] The following is an example of the method of optimizing a
wireless network that is consistent the method described above with
reference to FIG. 2. [0053] 1. The critical Hour is identified as
Hour 9 (as expected from the traffic model) [0054] 2. For cell
4.sub.--2, Hour 9, the available resources is below the threshold;
hence load balancing could help resolving it. [0055] 3. Best
Neighbor search result is Cell 194.sub.--1 [0056] 4. The Zone
accumulated DCR is recorded (32.94) before implementing any changes
[0057] 5. Change Cell 4_2 configuration as follows: [0058] a.
Increase the down tilt of the critical cell 4.sub.--2 by 1 Deg
[0059] b. Decrease the Power By 1.5 dB [0060] 6. Monitor the
performance for n days (In this case 5 days) [0061] 7. After n
days, the 5 days accumulated DCR is enhanced as the Zone
accumulated DCR is changed from 32.94 to 32.601 and the capacity
have not degraded [0062] 8. Decrease the down tilt of the best
neighbor 194.sub.--1 by 1 deg [0063] 9. Monitor the performance for
n days (In this case 5 days) [0064] 10. After n days, the 5 days
accumulated DCR is found to be degraded to be 32.675 However it is
still below the original accumulated DCR of 32.94 [0065] 11. Best
Neighbor search result is Cell 10.sub.--3 [0066] 12. Change Cell
4_2 configuration as follows: [0067] a. Increase the down tilt of
the critical cell 4.sub.--2 by 1 Deg [0068] b. Decrease the Power
By 1.5 dB [0069] 13. Monitor the performance for n days (In this
case 5 days) [0070] 14. After n days, the 5 days accumulated DCR is
enhanced as the Zone accumulated DCR is changed to 31.962 and the
capacity have not degraded [0071] 15. Decrease the down tilt of the
best neighbor 10.sub.--3 by 1 deg [0072] 16. Monitor the
performance for n days (In this case 5 days) [0073] 17. After n
days, the 5 days accumulated DCR is enhanced to be 31.866 [0074]
18. Repeat 11 to 14 and the 5 days accumulated DCR becomes 31.168
[0075] 19. Repeat 15 to 17 and the 5 days accumulated DCR becomes
30.997 [0076] 20. Now Cell 4_2 has free available resources and
load balancing will not help in increasing the capacity of the
network.
[0077] FIG. 3 illustrates a method for determining a critical zone
requiring optimizing of network parameters in accordance with an
embodiment of the invention. In step 301, neighbor lists are
collected for a critical cell/sector. The neighbor list includes
all the potential neighbor cell/sectors for a particular a
cell/sector, and it may include neighbor priorities as well. A
potential neighbor cell/sector is a cell/sector that provides
services to mobile equipment as part of a handover operation when
the mobile equipment is traveling from one coverage area to
another. The neighbor list can be stored in the network database
110.
[0078] The neighbor list can be stored in the network database 110
in the form of table that includes a list of cells and a
corresponding list of zones. For each critical cell site/sector
needing optimization, a local zone will be identified as the set of
the neighbor cell sites/sectors based on some criteria, which can
also be based on one or more performance metrics. A "cells table"
will be formed to contain all the cells in the local zones of all
the critical cells/sectors, and it will contain cell_id and
simple_zone_id=local_zone_id for each cell. A "simple zone list"
saves the checked/partially checked local zones during the search,
and it contains the simple zone id and the corresponding final
zone. The"cells list" saves the checked/partially checked cells
during the search, and it contains the cell_id and the
corresponding final zone.
[0079] In step 302, the cells table is sorted by simple zone_ID and
then by cell_ID. Initially both the cells list and simple zone list
are empty. For each entry in the cells table the following
operation take place. In step 303, an X zone reference is
determined from the cell list based on finding a cell_ID that
matches the cell_ID entered for a cell. In step 304, a Y zone
reference is determined from the simple zone list based on finding
a zone_ID that matches the zone_ID entered for the cell. Once the X
zone reference and Y zone reference are determined for the critical
cell, it then needs to be determined if the X zone reference and
the Y zone reference are included in a critical zone. In step 305,
it is determined if the X zone reference is in a critical zone. If
the X zone reference is in a critical zone, then in step 306 it is
determined if the Y zone reference is in a critical zone. If both
the X zone reference and the Y zone reference are included in a
critical zone, then in step 307 it is determined if the X zone
reference and the Y zone reference refer to the same zone. If the X
zone reference and the Y zone reference also refer to the same
zone, then in step 308, the cell_ID is added to this final critical
zone. In step 309, it is determined if any cells in the cells table
has been unchecked. If not, the process is ended in step 320. If
there are cells in the cells table that have not been checked, then
the remaining cells in the cells table are checked by returning to
step 303.
[0080] In step 307, if the X zone reference and the Y zone
reference are referring to the different zones, then a new critical
zone is created in step 310. In step 311, the X zone reference and
the Y zone are included in the new final critical zone, the cell
list in the database 110 is updated for the newly created zone
(i.e., by cell_ID and zone_ID) and the zone in the simple zone list
is updated for the newly created zone. Also, in step 312 the
previous zones for the X zone reference and the Y zone reference
are removed. The process then returns to step 309 where it is
determined if any cells in the cells table has been unchecked. If
not, the process is ended in step 320. However, if there are cells
in the cells table that have not been checked, then the remaining
cells in the cells table are checked by returning to step 303.
[0081] In step 306, if it is determined that the X zone reference
is in a critical zone, but the Y zone reference is not, then in
step 313 it is determined that the X zone reference is the final
critical zone, as in steps 314 and 308, the Y zone reference is
added to the final critical zone that includes X. The process then
returns to step 309 where it is determined if any cells in the
cells table has been unchecked. If not, the process is ended in
step 320. However, if there are cells in the cells table that have
not been checked, then the remaining cells in the cells table are
checked by returning to step 303.
[0082] In step 305, if it is determined that the X zone reference
is not in a critical zone then in step 315 it is determined if the
Y zone reference is in a critical zone. If it is determined that X
zone reference is not in a critical zone, but the Y zone reference
is in a critical zone, then in step 316, it is determined that the
Y zone reference is the final critical zone, as in steps 314 and
308, the X zone reference is added to the final critical zone that
includes the Y zone reference. The process then returns to step 309
where it is determined if any cells in the cells table has been
unchecked. If not, the process is ended in step 320. However, if
there are cells in the cells table that have not been checked, then
the remaining cells in the cells table are checked by returning to
step 303.
[0083] In step 315, if it is determined that the X zone reference
is not in a critical zone, and the Y zone reference is not in a
critical zone, then in step 317, a new critical zone is created
that includes the X zone reference and the Y zone reference. Then
in steps in steps 314 and 308, the IDs for the newly added zone are
added to cell list and simple zone list and the X zone reference
and the Y zone reference are added to a final critical zone. The
process then returns to step 309 where it is determined if any
cells in the cells table has been unchecked. If not, the process is
ended in step 320. However, if there are cells in the cells table
that have not been checked, then the remaining cells in the cells
table are checked by returning to step 303.
[0084] FIG. 4 illustrates a method for determining a best neighbor
cell in accordance with an embodiment of the invention. As noted
above, if a critical cell site/sector does not have adequate
available resources, then it is important (for performing network
optimization) to determine neighbor cell sites/sectors that can
assisting in addressing any degraded conditions
[0085] In step 401, the neighbor cells/sectors are determined based
on the cells list table in the database 110. In step 402, the
neighbor list is sorted by network statistics. As noted above,
network statistics may include, but are not limited to, key
performance Indicators (KPIs). An example of a KPI is the dropped
calls rate or handovers, which is the ratio between the failed
calls and the total number of calls requested. The network
statistics may also include, but are not limited to the
following:
[0086] Exemplary Switch Statistics [0087] UL and DL Stats For Each
Sector/Carrier: Load, Erlangs and Throughput [0088] Capacity For
Each Sector/Carrier [0089] Sensitive KPIs To Operators Per
Sector/Carrier Such as Dropped Calls and Blocked Calls [0090]
Location Of Most Users (Clusters) [0091] Year/Month/Day/Time [0092]
Cell ID [0093] Antenna ID [0094] Carrier Frequency [0095] Number Of
Established Calls [0096] Channel Elements (CE) Primary Use [0097] %
Primary Traffic CE Usage [0098] % Secondary Traffic CE Usage [0099]
Total CE Usage (Erlang) [0100] Peak # of Walsh Codes [0101] Soft
Handover Overhead % [0102] Soft or hard handover counts [0103] Peak
DL Power [0104] Number Of Dropped And Lost Calls [0105] Number Of
Blocked Calls [0106] UL Thermal Noise Floor (main) [0107] UL
thermal Noise Floor (diversity) [0108] Average DL Power [0109]
Pilot, Paging and Sync Channels Powers [0110] Peak Number of
Primary Walsh codes [0111] Reported Or Calculated Sector Load For
UL
[0112] Exemplary Network Parameters [0113] Site Latitude And
Longitude [0114] Type: Macro-Cell, Micro-Cell, Repeater [0115]
Handoff Parameters (T_Add, T_Drop, Tt_Drop, T_Comp) [0116] PA
Output Power [0117] Antenna Direction [0118] Antenna Height Above
Ground And Sea Level [0119] Antenna Model, Azimuth BW, Elevation
BW, Gain, Electrical And Mechanical Tilt [0120] PN Offset Per
Sector [0121] Morphology: Urban, Highway, Suburban, Rural, Dense
Urban [0122] Number Of RF Carriers Per Sector And Their Frequencies
[0123] Equipment Multi-Antenna Capability: Rx Diversity, STC, MIMO
[0124] Losses From PA Output To Antenna Ports If Applicable [0125]
Multi-Carriers To Antennas Mapping [0126] Technology: WIMAX, UMTS,
HSxPA, CDMA2000, 1xRTT, 1x-EVDO Rev. A, B or C, GSM, etc., And
Supported Features By The Equipment
[0127] In step 403, the neighbor cells are then grouped based on
available resources and network statistics. The grouped neighbor
cells are sorted based on network statistics. Then, in step 404,
the neighbor cells in the first group are ranked based on their
available resources. For example, the top neighbor cell
sites/sectors may have a high number of handovers with the critical
cell site/sector, or the top neighbor cell sites/sectors may have
antenna beams looking toward the critical site/sector. In step 405
the best neighbor cells/sectors in the group is determined. In step
406, it is determined if the best neighbor cell has adequate
available resources to address the degraded condition. If not, then
another best neighbor cell from the group is determined, as in step
405, which has resources available to address the degraded
condition. Once a best neighbor cell/sector is determined, then in
step 407, recommended modifications to the wireless network are
calculated. If the best neighbor is not found, the next group will
be searched using the same criteria.
[0128] As noted above, the calculated configuration modification
could be that, for example, the critical cell site/sector antenna
down tilt will be increased and/or the critical cell site/sector
transmitted power will be decreased; the critical cell site/sector
antenna pointing direction will be moved away from the neighbor
which has more available resources or away from a neighbor
cell/sector which has less available resources; and/or the critical
cell site/sector antenna beamwidth will be decreased; and/or the
critical cell site/sector transmitted power will be decreased to
compensate for the increase in gain cased by decreasing
beamwidth.
[0129] Additionally, the calculated configuration modification
could be that, for example, that the best neighbor cell site/sector
antenna down tilt will be decreased and/or the best neighbor cell
site/sector transmitted power will be increased; the best neighbor
cell site/sector antenna pointing direction will be moved towards
the critical cell site/sector and/or the best neighbor cell
site/sector antenna beamwidth will be increased; and/or the best
neighbor cell site/sector transmitted power will be increased to
compensate for the decrease in gain cased by increasing beamwidth.
The recommendations above can be implemented simultaneously or
sequentially or with time delay in between.
[0130] FIG. 5 is a more detailed description of optimization
apparatus 101 for performing the method of self-optimization as
previously described with reference to FIGS. 2-4. In FIG. 5, the
optimization apparatus 101 includes a memory 501, a processor 502,
user interface 503, application programs 504, communication
interface 505, and bus 506.
[0131] The memory 501 can be computer-readable storage medium used
to store executable instructions, or computer program thereon. The
memory 501 may include a read-only memory (ROM), random access
memory (RAM), programmable read-only memory (PROM), erasable
programmable read-only memory (EPROM), a smart card, a subscriber
identity module (SIM), or any other medium from which a computing
device can read executable instructions or a computer program. The
term "computer program" is intended to encompass an executable
program that exists permanently or temporarily on any
computer-readable storage medium as described above.
[0132] The computer program is also intended to include an
algorithm that includes executable instructions stored in the
memory 501 that are executable by one or more processors 502, which
may be facilitated by one or more of the application programs 504.
The application programs 504 may also include, but are not limited
to, an operating system or any special computer program that
manages the relationship between application software and any
suitable variety of hardware that helps to make-up a computer
system or computing environment of the self-optimization apparatus
501. General communication between the components in the
self-optimization apparatus 101 is provided via the bus 506. The
self-optimization algorithm as described with reference to FIGS.
2-4 can be stored, for example, in the memory 501 of the
self-optimization apparatus 101.
[0133] The user interface 503 allows for interaction between a user
and the self-optimization apparatus 101. The user interface 503 may
include a keypad, a keyboard, microphone, and/or speakers. The
communication interface 505 provides for two-way data
communications from the self-optimization apparatus 101. By way of
example, the communication interface 505 may be a digital
subscriber line (DSL) card or modem, an integrated services digital
network (ISDN) card, a cable modem, or a telephone modem to provide
a data communication connection to a corresponding type of
telephone line. As another example, communication interface 505 may
be a local area network (LAN) card (e.g., for Ethernet.TM. or an
Asynchronous Transfer Model (ATM) network) to provide a data
communication connection to a compatible LAN.
[0134] Further, the communication interface 505 may also include
peripheral interface devices, such as a Universal Serial Bus (USB)
interface, a Personal Computer Memory Card International
Association (PCMCIA) interface, and the like. The communication
interface 505 also allows the exchange of information across one or
more wireless communication networks. Such networks may include
cellular or short-range, such as IEEE 802.11 wireless local area
networks (WLANS). And, the exchange of information may involve the
transmission of radio frequency (RF) signals through an antenna
(not shown).
[0135] From the description provided herein, those skilled in the
art are readily able to combine software created as described with
the appropriate general purpose or special purpose computer
hardware for carrying out the features of the invention.
[0136] Additionally, it should be understood that various changes
and modifications to the presently preferred embodiments described
herein will be apparent to those skilled in the art. Such changes
and modifications can be made without departing from the spirit and
scope of the present subject matter and without diminishing its
intended advantages. It is therefore intended that such changes and
modifications be covered by the appended claim.
* * * * *