2
CLASS-BASED CARRIER RESELECTION
FIELD OF INVENTION
[0001] The present subject matter relates generally to wireless communication systems
and, particularly but not exclusively, to method for performing carrier reselection in a wireles5 s
communication system.
BACKGROUND
[0002] User equipments (UE), such as cellular phones, smart phones, and personal digital
assistants (PDAs), facilitate users with a variety of mobile communications services and
10 networking capabilities. Such UEs have seemingly become a ubiquitous part of today’s lifestyle.
The UEs allow data exchange between multiple users through network services provided by
various network operators. The network operators are faced with a challenge to meet user
demands at all places and all the time. With the rapid rise in the user demands, the network
operators deploy different types of radio access technologies (RAT), utilizing the different
15 communication standards, such as 2nd generation (2G), 3rd generation (3G), and 4th generation
(4G), to increase the capacity of the wireless networks.
[0003] However, in general, RAT technologies employing 4G is preferred more over
RAT technologies employing 3G or 2G by the users for obtaining high speed data connectivity
along with high quality of service (QoS). Such preference of the users imbalances the loads
20 between different types of RATs deployed in the wireless networks.
SUMMARY
[0004] This summary is provided to introduce concepts related to methods and systems
for performing carrier reselection in a wireless communication system. This summary is not
25 intended to identify essential features of the claimed subject matter nor is it intended for use in
determining or limiting the scope of the claimed subject matter.
[0005] In one implementation, a method for performing carrier reselection in a wireless
communication system is described. The method includes receiving, at a user equipment (UE), a
system information from a serving carrier. In an example, the system information includes a
3
plurality of class-based reselection parameters of a serving carrier and at least one neighboring
carrier. The plurality of class-based reselection parameters are set according to multiplicity of
factors, such as relative loading, priority, etc., to control reselection behavior and reselection
target based on a class assigned to the UE. The class is assigned to the UE based on service
parameters subscribed by the UE. In an example, the plurality of class-based reselectio5 n
parameters may be either common across all the carriers or specific to each carrier. Upon
receiving the system information, the UE measures signal characteristics of signals received at
the UE from the serving carrier and the at least one neighboring carrier. The measured signal
characteristics are then compared with the plurality of class-based reselection parameters
10 corresponding to the class assigned to the UE. Thereafter, the carrier reselection is performed
from the serving carrier to the at least one neighboring carrier based on the measured signal
characteristics comparison with the plurality of class-based reselection parameters.
[0006] In another implementation, a user equipment (UE) for carrier reselection in a
wireless communication system is described. The UE includes a radio frequency (RF) unit to
15 receive system information at the UE from the serving carrier. The system information includes a
plurality of class-based reselection parameters of the serving carrier and the at least one
neighboring carrier. The plurality of class-based reselection parameters are set according to
multiplicity of factors, such as relative loading, priority, etc., to control reselection behavior and
reselection target based on class assigned to the user. The class is assigned to the UE based on
20 service parameters subscribed by the UE. In an example, the plurality of class-based reselection
parameters may be either common across all the carriers or specific to each carrier. After
receiving the system information, a reselection module of the UE measures signal characteristics
of signals received at the UE from the serving carrier and the at least one neighboring carrier,
compares the measured signal characteristics with the plurality of class-based reselection
25 parameters corresponding to the class assigned to the UE, and performs carrier reselection from
the serving carrier to the at least one neighboring carrier based on the measured signal
characteristics comparison with the plurality of class-based reselection parameters.
BRIEF DESCRIPTION OF THE FIGURES
4
[0007] The detailed description is described with reference to the accompanying figures.
In the figures, the left-most digit(s) of a reference number identifies the figure in which the
reference number first appears. The same numbers are used throughout the figures to reference
like features and components. Some embodiments of system and/or methods in accordance with
embodiments of the present subject matter are now described, by way of example only, and wit5 h
reference to the accompanying figures, in which:
[0008] Fig. 1 illustrates a communication system for performing carrier reselection
process in a communication network, in accordance with an embodiment of the present subject
matter.
10 [0009] Fig. 2 illustrates a user equipment for performing the carrier reselection process,
in accordance with an embodiment of the present subject matter.
[0010] Fig. 3 illustrates a call-flow diagram for performing the carrier reselection process
in a communication network, in accordance with an exemplary embodiment of the present
subject matter.
15 [0011] Fig. 4 illustrates an exemplary method for performing the carrier reselection
process in a communication network, according to an embodiment of the present subject matter.
[0012] It should be appreciated by those skilled in the art that any block diagrams herein
represent conceptual views of illustrative systems embodying the principles of the present
subject matter. Similarly, it will be appreciated that any flow charts, flow diagrams, state
20 transition diagrams, pseudo code, and the like represent various processes which may be
substantially represented in computer readable medium and so executed by a computer or
processor, whether or not such computer or processor is explicitly shown.
DETAILED DESCRIPTION OF EMBODIMENTS
25 [0013] The methods and systems described herein can be implemented in systems
capable of performing carrier reselection in communication networks in accordance with the
different types of radio access technologies (RAT) utilizing the different communication
standards, such as 2G, 3G, and 4G. Further, the methods and systems described herein can be
5
implemented in any of the communication networks, such as Global System for Mobile
Communication (GSM) network, Universal Mobile Telecommunications System (UMTS)
network, Code Division Multiple Access (CDMA) network Long Term Evolution (LTE)
network. Although the description herein is with reference to certain communication networks,
the methods and systems may be implemented in other communication networks, albeit with 5 a
few variations, as will be understood by a person skilled in the art.
[0014] Nowadays, users or subscribers of communication networks, such as wireless
cellular networks, are becoming increasingly demanding in terms of the number of services
provided by network operators. Additional services and enhancements to existing services, like
10 video calling enabling face-to-face interactions, contribute in raising the quality of the service
being experienced by the users. One of the factors which directly contributes to the quality of
the experience by the users is the data transmission rate.
[0015] With an increasingly large number of users availing various high data rate
services provided by the network operators, the communication networks are faced with issues
15 related to capacity saturation, poor delivery Quality of Service (QoS), bad Quality of Experience
(QoE), ignorance to Grade of service (GoS) by users, etc. In an example, an optimal coverage
may not be available to the users at different time instances and at different geographic locations.
Due to lack of good coverage, a user may not be able to use some applications. In another
example, at certain times, the density of users utilizing the services provided by a wireless
20 network in a particular geographic location may be more than what the wireless network is
capable of catering to, resulting in the communication network operating at its near peak
capacity. When nearing the peak capacity, the communication network may either not be able to
provide services to each and every user, thereby affecting the Quality-of-Service (QoS) being
afforded to the users. In such overload situations, even when the users are catered to by the
25 network operators with good coverage, the data rate received by the users may be very less
resulting in a poor or sub-optimal QoS.
[0016] Generally, the poor QoS issue may arise as a result of deficient network planning
and inappropriate network load balancing mechanisms implemented by the network operators.
Existing mechanisms perform load balancing and network planning based on the presumption
6
that the load in a communication network due to a number of active users performing active data
transmission is highly correlated to a number of idle users that are not performing any data
transmission.
[0017] Further, from the state of the art, idle mode load balancing mechanism is proved
to be an effective and pro-active way of controlling active load on the communication network5 .
For example, in the idle mode load balancing mechanism, a user equipment (UE) receives
system information (SI) periodically transmitted from a serving carrier. Hereinafter, the serving
carrier may be referred to as carrier in which the UE currently receives a service, and the
neighboring carriers may be referred to as carriers other than the serving carrier and are not
10 limited to a geographical location with respect to the serving carrier and that can potentially
serve the user in future. Further, the system information includes list of carriers (serving and
neighboring carriers) available for reselection, priority value of the available carriers, radio
frequency (RF) reselection thresholds of the available carriers, etc. The priority value may be
referred to as a value defining the priority order of the available carriers for performing
15 reselection. Further, the RF reselection threshold may be referred to as a minimum signal
strength value or signal quality value defined in the communication network to ensure quality of
a RF signal in a process of transmitting or receiving data on a carrier. In an example, each carrier
may have a single RF reselection threshold or may have different RF reselection thresholds.
[0018] In an example, when an average data rate provided to the UE by a serving carrier
20 is expected to be X Kbps, any drop in the data rate below X Kbps may amount to poor QoS and
consequently require the reselection of the serving carrier. In an example, the data rate that can
be delivered to the UE depends on the RF signal strength of the serving carrier. In such a case,
where RF signal strength of the serving carrier becomes less than a RF threshold, the UE may
determine that it needs to reselect to a carrier, from amongst the other neighboring carriers.
25 Reselection of another carrier allows the UE to operate at a data rate as expected, say X Kbps.
Consequently, when reselected, the new serving carrier provides a signal characteristic superior
to that of the previous serving carrier. Examples of the signal characteristic may include
reference symbol received power (RSRP), reference symbol received quality (RSRQ), received
signal strength indicator (RSSI), etc.
7
[0019] The UE selects one of the neighboring carriers as the serving carrier as long as
that neighboring carrier has highest priority and has RF signal strength above the reselection
threshold; else the UE repeats the carrier reselection process for the next carrier in accordance
with the priority order received along the system information. The existing idle mode load
balancing mechanism, based on carrier priority order and carrier-based RF reselection threshold5 ,
is applicable to all UEs, irrespective of QoS or GoS subscribed by individual UEs.
[0020] Further, in another idle mode load balancing mechanism, to assure good Quality
of Service (QoS) or Grade of Service (GoS) to individual UEs, for example, subscribers who are
willing to pay higher fees, the network operators assign different types of GoS, such as a
10 Platinum Class, Gold Class, or Bronze Class, based on subscribed GoS or QoS. With this
assignment, users having higher GoS are given higher priority in the communication network
and thus guarantee high bit rate and QoS to the high class users all the time. However, for
assuring high bit rate and high QoS, in case of lower quality of signal strength on a serving
carrier, a percentage of idle mode UEs can be directed to carriers having lesser load. The
15 drawback of this idle mode load balancing mechanism is that a percentage of the idle mode UEs
from each class is selected for being directed to carriers having lesser load, irrespective of GoS
subscribed by individual idle mode UEs. So, there will be a percentage of users UEs with lower
GoS that would reselect to the target carrier at the cost of some higher GoS users that will be
forced to stay in the serving carrier because only a certain percentage of the overall users are
20 allowed to reselect.
[0021] Systems and methods for carrier reselection in a wireless communication network
are described hereinafter, in accordance with various exemplary implementations and
embodiments of the present subject matter in accordance with the present subject matter.
Although the description hereinafter is provided with reference to cellular networks, the systems
25 and method, of the present subject matter, may be implemented in other communication
networks providing data connectivity, albeit with a few variations, as will be understood by a
person skilled in the art.
[0022] In one implementation of the present subject matter, the methods and systems
according to the present subject matter may be implemented for processing of the system
8
information (SI) periodically received at the user equipment (UE) from the serving carrier. In an
example, the system information may include a list of carriers (including the serving carrier and
neighboring carriers) available for carrier reselection, priority values of the available carriers, a
plurality of class-based reselection parameters of each of the available carriers. In accordance
with the present subject matter, the plurality of class-based reselection parameters correspond t5 o
different classes of the UEs which itself is determined by QoS/GoS and or any other relevant
service parameters. For example, a carrier may imply that a class-based reselection parameter for
UE categorized as part of a Platinum Class is 0 RF signal strength value, for Gold Class is of 20
RF signal strength value, and for Bronze Class is of 50 RF signal strength value. That is, each
10 carrier may specify a class-based reselection parameter for each class assigned to the UEs based
on service parameters subscribed by the UEs.
[0023] Further, the steps for processing the system information include measuring signal
characteristics of the serving and candidate neighboring carrier(s), comparing the measured
signal characteristics with appropriate class-based reselection parameters corresponding to the
15 class assigned to the UE, and based on the comparison, performing a reselection from the serving
carrier to one of the candidate neighboring carriers.
[0024] In this way, by implementing the present subject matter, each class of UEs is
provided with different class-based reselection parameters, which in turn results into an optimum
idle mode load balancing. That is, class of the UE, which is determined and assigned on the basis
20 if the GoS, QoS and/or other relevant service parameters, is considered among the other things
for directing idle mode UEs to perform carrier reselection, or for inhibiting from performing
carrier reselection. For example, a UE ‘ABC’ has subscribed Platinum Class of 3G WCDMA
carrier and another UE ‘XYZ’ has subscribed Bronze Class and is currently being served using a
3G WCDMA carrier. For the present example, it may be assumed that a 4G LTE carrier in the
25 neighborhood is available with the 4G LTE carrier being the preferred carrier for the UE ‘ABC’
to be served. Now, say, the 3G WCDMA carrier is configured with class-based reselection
parameter for Platinum Class is that serving carrier strength should be less than 40 RF signal
strength value, and target 4G LTE carrier should of signal strength greater than 30 RF signal
strength value. For the Bronze Class UE ‘XYZ’, the class-based reselection parameter is set such
9
that serving carrier strength should be less than 50 RF signal strength value and target 4G LTE
carrier should of RF signal strength greater than 30 RF signal strength value. Thereafter, in the
present example, it may be assumed that the signal strength on the serving 3G WCDMA carrier
drops below the class-based reselection parameter of 50 RF signal strength value and there is a
4G LTE carrier available with signal strength greater than 30 RF signal strength value. In suc5 h
scenario, for performing load balancing on the 3G WCDMA carrier, the UE ‘ABC’ belonging to
Platinum Class would perform reselection from the 3G WCDMA carrier to the 4G LTE carrier
(preferred system) while the UE ‘XYZ’ stays back on the 3G WCDMA carrier allowing the 4G
LTE carrier to better serve the Platinum user. Thus, an optimum idle mode load balancing
10 mechanism is performed while considering GoS and QoS for the users willing to pay more than
others.
[0025] The above methods and systems are further described in conjunction with the
following figures. It should be noted that the description and figures merely illustrate the
principles of the present subject matter. It will thus be appreciated that those skilled in the art
15 will be able to devise various arrangements that, although not explicitly described or shown
herein, embody the principles of the present subject matter and are included within its scope.
[0026] Furthermore, all examples recited herein are principally intended expressly to be
for pedagogical purposes to aid the reader in understanding the principles of the present subject
matter and the concepts contributed by the inventor(s) to furthering the art, and are to be
20 construed as being without limitation to such specifically recited examples and conditions.
Moreover, all statements herein reciting principles, aspects, and embodiments of the present
subject matter, as well as specific examples thereof, are intended to encompass equivalents
thereof.
[0027] The manner in which the methods and systems of the present subject matter may
25 be implemented has been explained in details with respect to the Figs 1-3. While aspects of
described method(s) and system(s) of the present subject matter can be implemented in any
number of different computing systems, environments, and/or configurations, the embodiments
are described in the context of the following system(s).
10
[0028] Fig. 1 illustrates a wireless communication system 100, in accordance with an
exemplary embodiment of the present subject matter. The wireless communication system 100
includes a number of base stations, one of which 102 is shown in Fig. 1. The base station 102
may include fixed stations that communicate with communicating devices, and may also be
referred to as one or more Node B or evolved Node B (eNB), base stations, access points, etc5 .
Further, the base station 102 manages radio resources in a particular geographic area (shown
with dotted circle) using the one or more carriers 104, out of which, for example, two, carriers
104-1 and 104-2, are shown in Fig. 1. A carrier may be understood as a data communication
network operating at a particular operating frequency and with a particular Radio Access
10 Technology (RAT). In Fig. 1, the carriers 104-1 and 104-2 are configured in such a manner that
the carriers 104-1 and 104-2 geographically overlap each other and use different operating
frequencies.
[0029] Further, in addition to the number of base stations, the wireless communication
system 100 may also include entities capable of exchanging data to provide connectivity to
15 different communicating devices. Such entities may be implemented at the base station 102 for
providing communication connectivity to the users. Such entities may include Radio Network
Controller (RNC), Base Transceiver Station (BTS), Mobile Switching Centre (MSC), Short
Message Service Centre (SMSC), Base Station Subsystem (BSS), Home Location Register
(HLR), Visitor Location Register (VLR), Authentication Center (AuC), routers, and the like.
20 [0030] In an example, the base station 102 may communicate to multiple users through
user equipments (UE)s 106-1, 106-2, and 106-N, through a communication network, such as
cellular network or wireless network, having an uplink and a downlink. For the sake of clarity,
the multiple UEs 106-1, 106-2, …, 106-N are collectively referred to as UEs 106 and
individually as UE 106, hereinafter. Further, an uplink may be referred to as a communication
25 link from the UEs 106 to the BS 102, and a downlink may be referred to as a communication link
from the base station 102 to the UEs 106.
[0031] In an implementation of the present subject matter, the UE 106 may include a
radio frequency (RF) unit to transmit and receive RF signals from a carrier 104 of the base
station 102. Further, the UE 106 may include a processor(s) to perform carrier reelection process,
11
when required. The processor(s) may be implemented as one or more microprocessors,
microcomputers, microcontrollers, digital signal processors, central processing units, state
machines, logic circuitries, and/or any devices that manipulate signals based on operational
instructions. Among other capabilities, the processor(s) is configured to fetch and execute
computer-readable instructions stored in memory of the UE 106. Moreover, explicit use of th5 e
term “processor” should not be construed to refer exclusively to hardware capable of executing
software, and may implicitly include, without limitation, digital signal processor (DSP)
hardware, network processor, application specific integrated circuit (ASIC), field programmable
gate array (FPGA), read only memory (ROM) for storing software, random access memory
10 (RAM), non-volatile storage. Other hardware, conventional and/or custom, may also be included.
[0032] Further, the UE 106 may either be stationary at any geographic location or may be
a mobile device that may be moved from one geographic location to another. The UE 106 may
include, but are not limited to, mobile phone, Personal Digital Assistance (PDA), smartphones,
and the like. Further, the UE 106 may include devices capable of exchanging data to provide
15 connectivity to different communicating devices and computing systems. Such devices may
include, but are not limited to, data cards, mobile adapters, wireless (WiFiTM) adapters, routers, a
wireless modem, a wireless communication device, a cordless phone, a wireless local loop
(WLL) station, and the like. As the UE 106 may be stationary or mobile, the UE 106 may also be
understood to be a mobile station, a terminal, an access terminal, a subscriber unit, a station, etc.
20 [0033] In an implementation of the present subject matter, the communication network
between the base station 102 and the UEs 106 can be a wireless network or a cellular network, or
a combination thereof. The communication network can be a collection of individual networks,
interconnected with each other and functioning as a single large network (e.g., the internet or an
intranet). Examples of such individual networks include, but are not limited to, Global System
25 for Mobile Communication (GSM) network, Universal Mobile Telecommunications System
(UMTS) network, Personal Communications Service (PCS) network, Time Division Multiple
Access (TDMA) network, Code Division Multiple Access (CDMA) network, Next Generation
Network (NGN), IP-based network, Public Switched Telephone Network (PSTN), Wi-Fi
network and Long Term Evolution (LTE) network. Depending on the radio access technology
12
(RAT), the communication network may include various network entities, such as gateways,
routers; however, such entities have been omitted from the figures for the ease of understanding.
Although the network is described to be any communication network, the described methods and
systems have been illustrated with respect to a cellular network and may be implemented in other
networks providing data connectivity, albeit with a few variations, as will be understood by 5 a
person skilled in the art. The manner in which the reselection of serving carrier is further
described in conjunction with Fig. 2.
[0034] Fig. 2 illustrates exemplary components of the user equipment (UE) 106, in
accordance with an embodiment of the present subject matter. In one embodiment, the UE 106
10 facilitates the carrier reselection in a wireless communication system 100. The UE 106 may be
implemented as various computing devices, such as but not limited to a mobile phone, a smart
phone, a personal digital assistant (PDA), a digital diary, a tablet, a net-book, a laptop computer,
and the like. In one implementation, the UE 106 includes one or more processor(s) 202, I/O
interface(s) 204, and a memory 206 coupled to the processor(s) 202. The processor(s) 202 may
15 be implemented as one or more microprocessors, microcomputers, microcontrollers, digital
signal processors, central processing units, state machines, logic circuitries, and/or any devices
that manipulate signals based on operational instructions. Among other capabilities, the
processor(s) 202 is configured to fetch and execute computer-readable instructions stored in the
memory 206.
20 [0035] The I/O interface(s) 204 may include a variety of software and hardware
interfaces, for example, interfaces for peripheral device(s), such as a keyboard, a mouse, and an
external memory. Further, the I/O interfaces 204 may facilitate multiple communications within
a wide variety of protocol types including, operating system to application communication, inter
process communication, etc.
25 [0036] The memory 206 can include any computer-readable medium known in the art
including, for example, volatile memory, such as static random access memory (SRAM) and
dynamic random access memory (DRAM), and/or non-volatile memory, such as read only
memory (ROM), erasable programmable ROM, flash memories, hard disks, optical disks, and
magnetic tapes.
13
[0037] Further, the UE 106 may include module(s) 208 and data 210. The modules 208
and the data 210 may be coupled to the processor(s) 202. The modules 208, amongst other
things, include routines, programs, objects, components, data structures, etc., which perform
particular tasks or implement particular abstract data types. The modules 208 may also be
implemented as, signal processor(s), state machine(s), logic circuitries, and/or any other devic5 e
or component that manipulate signals based on operational instructions. In another aspect of the
present subject matter, the modules 208 may be computer-readable instructions which, when
executed by a processor/processing unit, perform any of the described functionalities. The
machine-readable instructions may be stored on an electronic memory device, hard disk, optical
10 disk or other machine-readable storage medium or non-transitory medium. In one
implementation, the computer-readable instructions can be also be downloaded to a storage
medium via a network connection.
[0038] In an implementation, the module(s) 208 includes a radio frequency (RF) module
212 and a reselection module 108, and other module(s) 214. The other module(s) 214 may
15 include programs or coded instructions that supplement applications or functions performed by
the UE 106.
[0039] The data 210 serves, amongst other things, as a repository for storing data
processed, received and generated by one or more of the components of the reselection module
108. The data 210 includes, for example, class-based reselection parameters 216, service
20 parameters 218, and other data 220. In one implementation, although the data 210 is shown
internal to the UE 106, it may be understood that the data 210 can reside in an external repository
(not shown in the figure), which may be coupled to the UE 106. The UE 106 may communicate
with the external repository through the I/O interface(s) 204 to obtain information from the data
210. In an example, the class-based reselection parameters 216 are employed to control
25 reselection behavior and reselection target based on class assigned to the UE 106. The class is
assigned to the UE 106 or derived at the UE 106 based on service parameters 218 subscribed by
the UE 106. In an example, the class-based reselection parameters 216 may be either common
across all the carriers or specific to each carrier.
14
[0040] In operation, when a UE, say UE 106-2, is initially powered on, the UE 106-2
starts operation in a radio resource control idle mode, i.e., idle mode. In the idle mode, the UE
106 is in a state in which the UE 106-2 is dormant or inactive. The UE 106-2, in the idle mode,
selects a radio access technology (RAT) to communicate with a communication network, for
example, a public land mobile network (PLMN), through which services are to be provided t5 o
the UE 106. Examples of RAT may include GSM EDGE radio access network (GERAN), an
UTRAN (UTRAN) network, LTE network, etc. However, the RAT is not limited thereto.
Information about the RAT and the PLMN may be selected by a user of the UE 106-2 or may be
stored in a universal subscriber identity module (USIM) of the UE 106-2.
10 [0041] After selection of the RAT and the PLMN, the UE 106-2 performs an initial
carrier selection process. The initial carrier selection process is performed by the UE 106-2 to
receive a service from a base station 102. In the initial carrier selection process, from amongst
one or more carriers in which a radio frequency (RF) signal associated with the selected RAT is
greater than a RF threshold, the UE selects a carrier, say carrier 104-2, having the greatest signal
15 strength or signal quality. The RF threshold may be referred to as a minimum signal strength
value or signal quality value defined in the communication network to ensure quality of a RF
signal in a process of transmitting or receiving data on a carrier. In general, the RF threshold may
vary depending on the RAT in use.
[0042] Once the carrier 104-2 is selected, the UE 106-2 receives system information (SI)
20 periodically from the selected carrier 104-2, i.e., serving carrier 104-2, of the base station 102.
Hereinafter, a serving carrier may be referred to as a carrier in which the UE 106 currently
receives a service, and a neighboring carrier may be referred to as a carrier other than the serving
carrier, can not limited to a geographical location with respect to the serving carrier, and can be a
serving carrier in the future. In an example, the system information includes basic and
25 indispensable information, for example, list of carriers (including serving carrier 104-2 and
neighboring carrier 104-1) that the UE 106-2 may reselect, a plurality of class-based reselection
parameters required in order to reselect a particular carrier, priority information, RF thresholds
information, load information, etc., that needs to be known to the UE 106-2 so as to access to the
base station 102. Therefore, the UE 106-2 has to completely receive the system information
15
before accessing to the base station 102 and always has to maintain latest system information.
Since the system information has to be known to all UEs within the serving carrier 104-2, the
base station 102 periodically transmits the system information to all the UEs.
[0043] Subsequent to the receipt of the system information from the base station 102, the
UE 106-2 may register its information to the communication network so as to receive services5 ,
for example, paging, from the communication network. However, the UE 106-2 is not required
to always register its information on the communication network. The UE 106-2 has to register
on the communication network when network information, for example, tracking area identity
(TAI) information, received through the system information is different from network
10 information known to or stored in the UE 106-2.
[0044] The UE 106-2 is then camped-on the serving carrier 104-2 until the signal
strength or the signal quality of a radio frequency (RF) signal received from the serving carrier
104-2 becomes lower than a class-based reselection parameter corresponding to a class
associated with the UE 106-2. In an example, the class can be either derived by the UE or
15 assigned by the network. The class can be assigned to the UE 106-2 based on service parameters,
such as GoS, Qos, QoE, or other relevant service parameters, subscribed by the UE 106-2.
Further, the term “camped-on a carrier refers that a UE tunes a central frequency of that carrier
and uses that carrier as the control channel. Therefore, the UE 106-2 can receive control
information such as a paging message and system information (SI) from the camped-on, serving,
20 carrier 104-2. The paging messages, in general, are used for information transfer from the base
station 102 to the UE 106-2.
[0045] Now, when the UE 106-2 is in idle state, it can receive the system information in
a broadcast message from the base station 102 of the serving carrier 104-2 using the RF module
212. The RF module 212 of the UE 106 is operably connected to the processor(s) 202, the I/O
25 interface(s) 204, and the memory 206 to transmit and receive RF signals from a carrier 104 of the
base station 102. In an example, the system information may include list of carriers (serving and
neighboring carriers) available for reselection, priority value of the available carriers, class-based
reselection parameters of the available carriers, etc.
16
[0046] Thereafter, the reselection module 108 of the UE 106-2 performs measurements
of signal characteristics of signals received from the serving carrier 104-2 and the neighbor
carriers which are the potential targets for reselection. Examples of the signal characteristic may
include reference symbol received power (RSRP), reference symbol received quality (RSRQ),
received signal strength indicator (RSSI), etc5 .
[0047] The reselection module 108 then compares the measured signal characteristics of
the serving carrier 104-2 and the neighbor carriers to an appropriate class-based reselection
parameter corresponding to a class assigned to the UE 106-2. Based on the comparison, the
reselection module 108 of the UE 106-2 may select one carrier, from amongst the carriers listed
10 in the system information, as new serving carrier based on appropriate comparisons with the
class-based reselection parameter corresponding to its class. Such process of reselecting any
other carrier as a serving carrier is known as carrier reselection process.
[0048] The carrier reselection process may be categorized based on RATs or frequency
characteristics:
15 · Intra-frequency carrier reselection : UE reselects to a carrier on the same RAT and the
same center frequency as that of the serving carrier.
· Inter-frequency carrier reselection : UE reselects to a carrier on the same RAT as that of
the serving carrier, and a different center frequency from that of the serving carrier.
· Inter-RAT carrier reselection : UE reselects to a carrier on a different RAT from that of
20 the serving carrier.
[0049] Thus, as described, in accordance with the present subject matter, the class-based
reselection parameter is not merely based on the strength or quality of received signal, but also
based on the class assigned to the UE 106-2. The class assigned to the UE is based on service
parameters like the Quality of Service (QoS) and Grade of Service (GoS) allocated to the UE
25 106-2 and other relevant service parameters. The class-based reselection parameter ensures that
the relevant service parameters are considered while performing a carrier reselection process.
[0050] In accordance with an implementation of the present subject matter, to provide the
assured service based on the service parameters like GoS, application QoS and the like, the
17
network operators may assign different classes to the users. Thus, in accordance with the present
subject matter, each carrier is configured with a plurality of class-based reselection parameters
corresponding to each class. For example, a serving carrier is configured in such a manner that a
class-based reselection parameter for Class 1 is of 0 RF signal strength value, for Class 2 is of 20
RF signal strength value, and for Class 3 is of 50 RF signal strength value. Thus, with differen5 t
class-based reselection parameters, under the same RF conditions, different classes of UEs can
be optimally distributed across the available carriers to maximize the user satisfaction and ensure
that service quality that is assured is delivered. For example, with such configuration of the
carriers, the communication network is able to influence a specific class of UEs to perform the
10 carrier reselection process and others to avoid attempting reselection.
[0051] In this way, an optimum load balancing mechanism is achieved while providing
service to the users who have been assured of the same based on their premium subscription or
QoS requirements of applications. That is, by the implementation of the present subject matter, a
load balancing mechanism is proposed in which the service parameters like GoS, QoS are
15 considered, among the other things, before performing the carrier reselection process.
[0052] Now, once it is identified that the carrier reselection process is to be performed
and a target serving carrier is selected based on the class-based reselection parameters, proposed
by the present subject matter, and other parameters like priority associated with the carrier, the
UE 106-2 reselects to the target serving carrier, from amongst the different carriers listed in the
20 system information. Thus, a carrier that has signal strength and signal quality that satisfies the
reselection criterion based on the class-based reselection parameters configured for the class
assigned to the UE and is of the highest priority order amongst the suitable candidates may be
selected by the UE 106-2 for providing service. The UE 106-2 is then camped-on a selected
target serving carrier that would be serving the UE 106-2.
25 [0053] In one implementation of the present subject matter, the plurality of class-based
reselection parameters can be configured on the carriers by extending the current standards of
communication to specify reselection parameters on per UE class basis. For example, in the
current LTE specification 3GPP TS 36.331, the IE SystemInformationBlockType5 contains
information relevant for inter-frequency carrier re-selection, i.e., information about other
18
E-UTRA frequencies and inter-frequency neighboring carriers relevant for carrier re-selection. In
the current LTE specification, amongst others, the following parameters control at what is the
bias at a UE to reselect to a particular LTE carrier:
· q-RxLevMin : Minimum required RSRP level in a carrier.
· threshX-High : RSRP Threshold for determining reselection towards a carrier wit5 h
higher priority than the serving carrier.
· threshX-Low : RSRP Threshold for determining reselection towards a carrier with
lower priority than the serving carrier.
· q-QualMin : Minimum required RSRQ level in a carrier.
10 · threshX-HighQ : RSRQ Threshold for determining reselection towards a carrier with
higher priority than the serving carrier.
· threshX-LowQ : RSRQ Threshold for determining reselection towards a carrier with
lower priority than the serving carrier.
15 [0054] An excerpt of the IE in the current LTE specification is reproduced below:
-- ASN1START
SystemInformationBlockType5 ::= SEQUENCE {
interFreqCarrierFreqList InterFreqCarrierFreqList,
...,
lateNonCriticalExtension OCTET STRING OPTIONAL -- Need
OP
}
InterFreqCarrierFreqList ::= SEQUENCE (SIZE (1..maxFreq)) OF
InterFreqCarrierFreqInfo
InterFreqCarrierFreqInfo ::= SEQUENCE {
dl-CarrierFreq ARFCN-ValueEUTRA,
q-RxLevMin Q-RxLevMin,
p-Max P-Max OPTIONAL, -- Need
OP
t-ReselectionEUTRA T-Reselection,
t-ReselectionEUTRA-SF SpeedStateScaleFactors OPTIONAL, -
- Need OP
threshX-High ReselectionThreshold,
threshX-Low ReselectionThreshold,
allowedMeasBandwidth AllowedMeasBandwidth,
presenceAntennaPort1 PresenceAntennaPort1,
19
cellReselectionPriority CellReselectionPriority
OPTIONAL, -- Need OP
neighCellConfig NeighCellConfig,
q-OffsetFreq Q-OffsetRange DEFAULT dB0,
interFreqNeighCellList InterFreqNeighCellList OPTIONAL,
-- Need OR
interFreqBlackCellList InterFreqBlackCellList OPTIONAL,
-- Need OR
...,
[[ q-QualMin-r9 Q-QualMin-r9 OPTIONAL, -- Need
OP
threshX-Q-r9 SEQUENCE {
threshX-HighQ-r9 ReselectionThresholdQ-r9,
threshX-LowQ-r9 ReselectionThresholdQ-r9
} OPTIONAL -- Cond
RSRQ
]]
}
InterFreqNeighCellList ::= SEQUENCE (SIZE (1..maxCellInter)) OF
InterFreqNeighCellInfo
InterFreqNeighCellInfo ::= SEQUENCE {
physCellId PhysCellId,
q-OffsetCell Q-OffsetRange
}
InterFreqBlackCellList ::= SEQUENCE (SIZE (1..maxCellBlack)) OF
PhysCellIdRange
-- ASN1STOP
[0055] In accordance with the present subject matter, the above excerpt would be
modified as follows to allow the specification of different class-based reselection parameters to
influence which class of UEs reselect to which carrier.
-- ASN1START
SystemInformationBlockType5 ::= SEQUENCE {
interFreqCarrierFreqList InterFreqCarrierFreqList,
...,
lateNonCriticalExtension OCTET STRING OPTIONAL -- Need
OP
}
InterFreqCarrierFreqList ::= SEQUENCE (SIZE (1..maxFreq)) OF
InterFreqCarrierFreqInfo
InterFreqCarrierFreqInfo ::= SEQUENCE {
dl-CarrierFreq ARFCN-ValueEUTRA,
20
perClassq-RxLevMin SEQUENCE (SIZE (1..maxUEClass)) OF QRxLevMin,
p-Max P-Max OPTIONAL, -- Need
OP
t-ReselectionEUTRA T-Reselection,
t-ReselectionEUTRA-SF SpeedStateScaleFactors OPTIONAL, -
- Need OP
perClassthreshX-High SEQUENCE (SIZE (1..maxUEClass)) OF
ReselectionThreshold,
perClassthreshX-Low SEQUENCE (SIZE (1..maxUEClass)) OF
ReselectionThreshold,
allowedMeasBandwidth AllowedMeasBandwidth,
presenceAntennaPort1 PresenceAntennaPort1,
cellReselectionPriority CellReselectionPriority
OPTIONAL, -- Need OP
neighCellConfig NeighCellConfig,
q-OffsetFreq Q-OffsetRange DEFAULT dB0,
interFreqNeighCellList InterFreqNeighCellList OPTIONAL,
-- Need OR
interFreqBlackCellList InterFreqBlackCellList OPTIONAL,
-- Need OR
...,
[[ perClassq-QualMin-r9 SEQUENCE (SIZE (1..maxUEClass)) OF
Q-QualMin-r9 OPTIONAL, -- Need OP
threshX-Q-r9 SEQUENCE {
perClassthreshX-HighQ-r9 SEQUENCE (SIZE (1..maxUEClass))
OF ReselectionThresholdQ-r9,
perClassthreshX-LowQ-r9 SEQUENCE (SIZE
(1..maxUEClass)) OF ReselectionThresholdQ-r9
} OPTIONAL -- Cond
RSRQ
]]
}
InterFreqNeighCellList ::= SEQUENCE (SIZE (1..maxCellInter)) OF
InterFreqNeighCellInfo
InterFreqNeighCellInfo ::= SEQUENCE {
physCellId PhysCellId,
q-OffsetCell Q-OffsetRange
}
InterFreqBlackCellList ::= SEQUENCE (SIZE (1..maxCellBlack)) OF
PhysCellIdRange
-- ASN1STOP
[0056] In the above modified specification in accordance with the present subject matter,
maxUEClass is a number of UE classes defined in the system. The UEs may be assigned one of
the UE classes. In an example, a UE may also determine its class by alternate with or without
21
explicit assignment from the network. Let's assume that two UE classes are defined, then
perClassthreshX-High would be a sequence (array) of two values (between 0 and 63) of
thresholds. Each threshold value corresponding to a particular UE class. For example, say the
perClassThreshX-High is defined as array [0, 63] for carrier ‘ABC’ implying that threshold value
for UE class 0 is ‘0’ (lower barrier) and threshold value for UE class 1 is ‘63’ (higher barrier)5 .
Similarly, say the perClassThreshX-High is defined as array [63, 0] for another carrier ‘XYZ’
implying that threshold value for UE class 0 is ‘63’ (higher barrier) and threshold value for UE
class 1 is ‘0’ (lower barrier). With this configuration of the carriers, the UEs in class 0 may
prefer to select the carrier ‘ABC’ and UEs in class 1 may prefer to select carrier ‘XYZ’. Hence,
10 network is able to control UEs of which specific classes reselect to which target carrier.
[0057] By controlling the thresholds as the class-based reselection parameters, the
network can control which class of UEs does the reselection and which of the classes are made to
stay back in the serving carrier.
[0058] In an example, the carrier ‘ABC’ can be a macro-cell carrier and the carrier
15 ‘XYZ’ can be a small-cell carrier, and vice versa. In the said example, the small-cell may
represent a deployments like, but not limited to, micro-cell, pico-cell, femto-cell of the same or
different air interface technology Hence, the current mechanism can control the traffic
distribution between the micro-cell carrier and the small-cell carrier in an
LTE/WiFi/WCDMA/CDMA Het-Net scenario.
20 [0059] Further, other class-based reselection parameters like perClassq-RxLevMin,
perClassq-QualMin, perClassthreshX-HighQ, and perClassthreshX-LowQ can be set with
different values corresponding to different UE classes to influence which UE class selects which
available carrier.
[0060] Yet further, although the present subject matter has been introduced in terms of
25 parameters relevant for HRPD and LTE, the present subject matter can be applied to
interworking between Wi-Fi, CDMA2000-1x, UMTS and GERAN with LTE as well. Thus, the
present subject matter is applicable to both intra-RAT and Inter-RAT multi-carrier idle mode
reselection.
[0061] Fig. 3 illustrates a call-flow diagram 300 for performing the carrier reselection
30 process in communication networks, in accordance with an exemplary embodiment of the
22
present subject matter. The various arrow indicators used in the call-flow diagram 300 depict the
transfer of signal/information between a base station 102 and a user equipment (UE) 106. In
many cases, multiple network entities besides those shown may lie between the entities,
including transmitting stations, and switching stations, although those have been omitted for
clarity. Similarly, various acknowledgement and confirmation network responses may also b5 e
omitted for clarity.
[0062] In one implementation as depicted in Fig. 2, in step 310, the base station 102
transmits a system information in a broadcast message to the UE 106 when the UE 106 is in an
idle state. In an example, the system information may be received by a RF module 212 of the UE
10 106. Further, in an example, the system information may include list of carriers (serving and
neighboring carriers) available for reselection, priority value of the available carriers, class-based
reselection parameters of the available carriers, etc. In an example, the class-based reselection
parameters may include, but not limited to, priority information, load information, RF thresholds
information, and other related information of the carriers (serving and neighboring carriers)
15 available for carrier reselection. The class-based reselection parameters are set according to
multiplicity of parameters, such as relative loading on a carrier, priority of a carrier, number of
UEs camped on a carrier, type of UEs camped on a carrier, etc., to control reselection behavior
and reselection target based on class assigned to the UE 106. The class is assigned to the UE 106
based on service parameters subscribed by the UE 106. Further, in an example, the class-based
20 reselection parameters may be either common across all the carriers or specific to each carrier.
[0063] In an alternative implementation, the class-based reselection parameters can be
provided to UE 106 in a unicast message when the UE is in a connected state. The class-based
reselection parameters will then be used later when the UE moves to idle state for idle mode
reselection.
25 [0064] In step 320, the reselection module 108 of the UE 106 performs downlink
measurements on the signals received from the serving carrier and the neighboring carriers to
measure signal characteristics. Examples of the signal characteristics may include reference
symbol received power (RSRP), reference symbol received quality (RSRQ), received signal
strength indicator (RSSI), etc. The UE 106 may select one carrier, from amongst the candidate
30 carriers listed in the system information, as a target serving carrier based on the measured signal
23
characteristics comparison with appropriate class-based reselection parameters corresponding to
a class assigned to the UE 106.
[0065] Further, in step 330, the reselection module 108 of the UE 106 determines
whether the carrier reselection process is to be performed or not. For example, in case the
measured signal characteristics pass the class-based reselection parameter of a target servin5 g
carrier, the UE 106 may perform the carrier reselection process in step 330; otherwise, the UE
106 stays back in the current serving carrier.
[0066] Fig. 4 illustrates an exemplary method 400 for performing the carrier reselection
process in a communication network, according to an embodiment of the present subject matter.
10 The order in which the method 400 is described is not intended to be construed as a limitation,
and any number of the described method blocks can be combined in any order to implement the
method 400, or an alternative method. Additionally, individual blocks may be deleted from the
method without departing from the scope of the present subject matter described herein.
Furthermore, the method 400 can be implemented in any suitable hardware, software, firmware,
15 or combination thereof.
[0067] The method 400 may be described in the general context of computer executable
instructions. Generally, computer executable instructions can include routines, programs, objects,
components, data structures, procedures, modules, functions, etc., that perform particular
functions or implement particular abstract data types. The method may also be practiced in a
20 distributed computing environment where functions are performed by remote processing devices
that are linked through a communication network. In a distributed computing environment,
computer executable instructions may be located in both local and remote computer storage
media, including memory storage devices.
[0068] A person skilled in the art will readily recognize that steps of the method can be
25 performed by programmed computers. Herein, some embodiments are also intended to cover
program storage devices, for example, digital data storage media, which are machine or
computer readable and encode machine-executable or computer-executable programs of
instructions, wherein said instructions perform some or all of the steps of the described method.
The program storage devices may be, for example, digital memories, magnetic storage media,
30 such as a magnetic disks and magnetic tapes, hard drives, or optically readable digital data
24
storage media. The embodiments are also intended to cover both communication network and
communication devices configured to perform said steps of the exemplary method.
[0069] Referring to Fig. 4, at block 402, a radio frequency (RF) module 212 of the user
equipment (UE) 106 receives system information (SI) in a broadcast message periodically from a
serving carrier, for example, serving carrier 104-1, of the base station 102. In an example, th5 e
system information includes basic and indispensable information, for example, list of carriers
(including serving carrier and neighboring carriers) that the UE 106 may reselect, class-based
reselection parameters required in order to reselect a target serving carrier, priority information,
load information, etc., that needs to be known to the UE 106 so as to access to the base station
10 102. In an example, the class-based reselection parameters are set according to multiplicity of
factors, such as relative loading, priority, etc., to control reselection behavior and reselection
target based on class assigned to the UE 106. The class is assigned to the UE 106 or derived at
the UE 106 based on service parameters subscribed by the UE 106. In an example, the classbased
reselection parameters may be either common across all the carriers or specific to each
15 carrier.
[0070] At block 404, the reselection module 108 of the UE 106 performs downlink
measurements on signals received from the serving carrier and the neighboring carriers to
measure signal characteristics. Examples of the signal characteristics may include reference
symbol received power (RSRP), reference symbol received quality (RSRQ), received signal
20 strength indicator (RSSI), etc.
[0071] At block 406, the reselection module 108 may compare the measured signal
characteristics of the signals received from the serving carrier and the neighboring carriers with a
plurality of class-based reselection parameters corresponding to a class assigned to the UE 106.
[0072] At block 408, the reselection module 108 of the UE 106 may select one carrier,
25 from amongst the candidate carriers listed in the system information, as a target serving carrier
based on the signal characteristics comparison with the class-based reselection parameter. As
described earlier, in accordance with the present subject matter, the class-based reselection
parameter is based on the class assigned to the UE 106-2. The class assigned to the UE is based
on service parameters like the Quality of Service (QoS) and Grade of Service (GoS) allocated to
30 the UE 106-2 and other relevant service parameters. Thus, the class-based reselection parameter
25
ensures that the relevant service parameters are considered while performing the carrier
reselection process.
[0073] Although the subject matter has been described with reference to specific
embodiments, this description is not meant to be construed in a limiting sense. Various
modifications of the disclosed embodiments, as well as alternate embodiments of the subjec5 t
matter, will become apparent to persons skilled in the art upon reference to the description of the
subject matter. It is therefore contemplated that such modifications can be made without
departing from the spirit or scope of the present subject matter as defined.
26

I/We claim:
1. A method for performing carrier reselection by a user equipment (UE) (106) in a wireless
communication system (100), the method comprising:
receiving system information at the UE (106) from a serving carrier, wherein th5 e
system information includes a plurality of class-based reselection parameters for controlling
carrier reselection based on a class assigned to the UE (106), the class being assigned based
on service parameters subscribed by the UE (106);
measuring signal characteristics of signals received from the serving carrier and at
10 least one neighboring carrier;
comparing the measured signal characteristics of the serving carrier and the at least
one neighboring carrier with the plurality of class-based reselection parameters
corresponding to the class assigned to the UE (106); and
performing carrier reselection from the serving carrier to the at least one neighboring
15 carrier based on the comparison.
2. The method as claimed in claim 1, wherein the serving carrier is one of a macro cell carrier
and small cell carrier, and wherein the at least one neighbor carrier is one of a macro cell
carrier and small cell carrier.
20
3. The method as claimed in claim 1, wherein the plurality of class based reselection parameters
include priority information and radio frequency (RF) thresholds information corresponding
to the serving carrier and the at least one neighboring carrier.
25 4. The method as claimed in claim 1, wherein based on the comparing, the method further
comprises:
prior to performing carrier reselection, selecting the at least one neighboring carrier
for performing the carrier reselection based on the plurality of class-based reselection
parameters associated with the serving carrier and the at least one neighboring carrier.
30
27
5. The method as claimed in claim 1, wherein the performing comprises performing one of
intra-frequency carrier reselection, inter-frequency carrier reselection, and inter radio access
technologies (RAT) carrier reselection.
6. The method as claimed in claim 1, wherein the UE (106) is in a radio resource control idl5 e
mode.
7. The method as claimed in claim 1, wherein the signal characteristics comprise one of a
reference symbol received power (RSRP), a reference symbol received quality (RSRQ), and
10 a received signal strength indicator (RSSI).
8. The method as claimed in claim 1, wherein the method further comprises:
setting the plurality of reselection parameters for distribution of different classes of UEs
on the serving carrier and the at least one neighboring carrier, based on one of,
15 load on a carrier,
number of UEs camped on a carrier,
type of UEs, and
properties of applications enabled on the UEs associated with a carrier.
20 9. The method as claimed in claim 1, wherein the method further comprises setting the plurality
of class-based reselection parameters according to relative loading and priority.
10. The method as claimed in claim 1, wherein the method further comprises setting the plurality
of class-based reselection parameters common across all carriers.
25
11. The method as claimed in claim 1, wherein the method further comprises setting the plurality
of class-based reselection parameters specific to each carrier.
12. A user equipment (UE) (106) for performing carrier reselection in a wireless communication
30 system (100), the UE (106) comprising:
28
a processor (202);
a radio frequency (RF) module (212), coupled to the processor (202), to receive
system information at the UE (106) from a serving carrier, wherein the system information
includes a plurality of class-based reselection parameters associated with the serving carrier
and at least one neighboring carrier, wherein the plurality of class-based reselectio5 n
parameters control carrier reselection based on a class assigned to the UE (106), the class
being assigned based on service parameters subscribed by the UE (106),
a reselection module (108), coupled to the processor (202), to:
measure signal characteristics of signals received from the serving carrier and
10 the at least one neighboring carrier,
compare the measured signal characteristics with the plurality of class-based
reselection parameters corresponding to the class assigned to the UE, and
perform carrier reselection from the serving carrier to the at least one
neighboring carrier based on the comparison.
15
13. The UE (106) as claimed in claim 12, wherein the UE (106) is in a radio resource control idle
mode.
14. The UE (106) as claimed in claim 12, wherein the serving carrier is one of a macro cell
20 carrier and small cell carrier, and wherein the at least one neighbor carrier is one of a macro
cell carrier and small cell carrier.
15. The UE (106) as claimed in claim 12, wherein the plurality of class-based reselection
parameters include priority information and radio frequency (RF) thresholds information
25 corresponding to the serving carrier and the at least one neighboring carrier.
16. The UE (106) as claimed in claim 12, wherein the reselection module (108) selects the at
least one neighboring carrier for performing the carrier reselection based on the class-based
reselection parameters associated with the serving carrier and the at least one neighboring
30 carrier.
29
17. The UE (106) as claimed in claim 12, wherein the reselection module (108) performs one of
intra-frequency carrier reselection, inter-frequency carrier reselection, and inter radio access
technologies (RAT) carrier reselection.
5
18. The UE (106) as claimed in claim 12, wherein the signal characteristics comprise one of a
reference symbol received power (RSRP), a reference symbol received quality (RSRQ), and
a received signal strength indicator (RSSI).
10 19. The UE (106) as claimed in claim 12, wherein the plurality of reselection parameters are set
for distribution of different classes of UEs on the serving carrier and the at least one
neighboring carrier, based on one of:
load on a carrier,
number of UEs camped on a carrier,
15 type of UEs, and
properties of applications enabled on the UEs associated with the carrier.
20. The UE (106) as claimed in claim 12, wherein the plurality of class-based reselection
parameters are set according to relative loading and priority.
20
Dated this 17 January 2014
JAYA PANDEYA
25 IN/PA-1345
AGENT FOR THE APPLICANT
To
The Controller of Patents
The Patents Office at New Delhi
30