Title of Invention

METHODS FOR RECOMMENDED AND ACTIVE SET SELECTION FOR HANDOFF IN WIRELESS MULTIMEDIA NETWORKS

Abstract In this invention, a system and method are proposed for handoff in the wireless multimedia networks. Handoff process being part of signaling system is well known in wireless networks of different types. However in this invention, handoff process is extended to wireless multimedia services, wherein constraints are posed by the application requirements such as in VOIP, video streaming, web browsing, QOS constraints, ftp, etc. The QoS requirements are statistical in nature. For example, typically it is desired that less than 2% of VoIP flows suffer a maximum delay of 30ms, less than 2% of FTP users obtain an average rate (throughput) of less than 9600 bps, less than 5% of MPEG-4 flows suffer a delay of greater than 150ms and a delay jitter greater than 1ms and so on. In the current IEEE 802.16e standard to support mobility in broadband wireless access networks, there are no efficient mechanisms mentioned to maintain the QoS requirements of flows during handoff. An efficient system and methods are invented to meet the requirement for Quality of services in VOIP, Video streaming, ftp, etc. during active set selection for the handoff. The handoff sequence applying our proposed mechanisms for the network driven handoff and the mobile driven handoff are shown in Figures 10 and 11, respectively.
Full Text

FIELD OF TECHNOLOGY
This invention in general relates to the field of mobility and handoff management in
i wireless networks (and specifically for IEEE802.16e mobile broadband wireless
access networks). More specifically this invention relates to the methods and system
for recommended and active set selection for handoff in wireless multimedia
; networks
DESCRIPTION OF THE RELATED ART
A schematic diagram of a wireless network is shown in Figure 1. Here, MT is the mobile terminal, which is also referred to as MSS, BS is the base station and CS is the control server. The medium access control MAC standard for this type of networks is described in www.ieee802.org/16/ the IEEE standard 802.16-2001, part 16: Air interface for fixed broadband wireless access systems.
In a wireless network, BS serves packets over the air-link for MT. BS is connected to •the CS using a wireline link and the memory at the BS is usually much smaller than that at the CS. The CS gets IP packets, fragments those to MAC packets and sends those to BS. In an IEEE 802.16 WMAN network, time is typically divided into fixed length time slots. The multiple access schemes are TDMA with TDD or FDD. The time is divided into frames, which, in turn, is divided into discrete slots. Each of these slots is of same length. Each mobile terminal informs the base station about its basic capabilities, which includes the types of services it can support, the buffering capabilities and the ability to support different MAC states. In addition, MT can also inform the BS about the rate at which it can accept data in each of the slots on forward link and the channel conditions measured and that can be tolerated. The MAC in such networks is connection oriented, with each connection being identified by a unique connection identifier (CID). The MAC consists of several convergence sub-layers (CL) that specify the type of traffic and the related quality-of-service (QoS) parameters like delay bound, latency, jitter, packet loss and throughput. The typical convergence sub-layers are the ATM CL and the packet CL. The packet CL includes

IPv4, IPv6 connections, Ethernet connections and the virtual LAN (VLAN) connections. There is a scheduler at the BS which schedules these packets over the air for mobile stations. Resource allocation and negotiation is performed by each MT by specifying the required bandwidth, and by each BS by allocating or rejecting requests depending on the availability of resources.
The handoff process and the related signaling messages are explained in Figures 2 and 3. Figure 2 shows the handoff without the assistance of the CS, while Figure 3 shows the handoff with the assistance of the CS. Here, BS #1 is the currently serving BS. NBRADV is the neighbor advertisement, which gives the neighboring set to the MS. SCN_REQ is the scan request which the MS issues to the currently serving BS, i.e., BS #1. BS #1 responds with a scan response SCNJRSP. The MS scans all the neighboring BSs and gives a candidate set to BS #1. BS #1 issues a handoff pre-notification HO_PRN to all the BSs in the candidate set and obtains their QoS capabilities through a HO_PRN-RSP response. The QoS capabilities are forwarded to the MS, which picks the BS with the best QoS capabilities and informs the serving BS about the target BS. The mobile first dissociates with BS #1 and then ; re-enters the network into the cell with BS #2.
To support mobility, it is not only important to maintain the set of ongoing flows from/to the mobile, but also important to maintain the QoS obtained by all the applications handled by the MT during handoff. The latency involved due to handoff because of disassociation of an MT from a BS and re-entry by association with another BS should also be below a limit specified by the application. For this purpose, it is essential to have efficient handoff mechanisms to control traffic flows in both directions over the air interface during handoff.
LIMITATIONS
Currently, the serving BS forwards the basic capabilities of the target BS to the MS. However there is no efficient mechanism known to decide on the target BS so as to

maintain the QoS of the flows. In this invention, we propose some mechanisms for determining the recommended set from the candidate set. Our proposed mechanisms provision for both base station driven (or network driven) as well as mobile driven handoff.
OBJECTS OF THE INVENTION
It is the primary object of the invention to invent a system and method for handoff in wireless multimedia network from the active set derived from the quality of services capabilities requirement and the negotiations.
It is another object of invention to invent a method wherein the existing limitation of BS and MS of maintaining the QOS flow information so that the handoff mechanism can be carried out based on QOS capability information.
It is another object of the invention to invent a method for creating recommended set at BS from the candidate set for handoff based on QOS constraints.
It is another object of the invention to invent a method by which the present limitations in the handoff process is tackled so as to control traffic flow and efficiently maintain Quality of service on wireless multimedia network.
It is another object of the invention to provide the necessary changes to be made in the NBR_ADV message in IEEE 802.16e standards to incorporate the mechanisms proposed in the invention.
Further objects of the invention will be clear from the ensuing description.

SUMMARY OF THE INVENTION
One mechanism to maintain the wireless connectivity and reduce latency during handoff is to deploy a logical make before break (MBB) handoff mechanism where an MT measures the carrier-to-interference noise ratio (CINR) from all its associated BSs and choose the BS with the maximum value of CINR. This involves parallel measurements of CINR from all associated BSs. The currently serving BS advertises the neighboring BS to the MT, which then synchronizes and measures the CINR from all neighboring BS. A subset of the neighboring BS called as the candidate set is chosen by the MT. The candidate set is the set of BS at which the CINR is above a specified threshold for the application. The BS selects a subset of the candidate set called recommended set and informs the MT about the recommended set. The selection of recommended set form the candidate set is based on CINR measurements with the possibility of including QoS capabilities.
The MBB handoff procedure and the corresponding signals without and with the assistance of the CS are shown in Figures 4 and 5, respectively. Here, BS #1 is the currently serving BS. NBR_ADV is the neighbor advertisement, which gives the neighboring set to the MS. SCN_REQ is the scan request which the MS issues to the currently serving BS, i.e., BS #1. BS #1 responds with a scan response SCN_RSP. The MS scans the neighboring set of BS and responds with a candidate set. The BS obtains the QoS capabilities of the neighboring BS and could choose a recommended set for the MS, or could correspond the information to the MS which negotiates with the neighboring BS and chooses a recommended set of BS. The MS picks one of the BS from the recommended set and undergoes a make before break handoff to the chosen BS (e.g., BS #2), and then dissociates with BS #1.
The network assisted MBB handoff procedure works as follows. Here, the BS selects a subset of the neighboring set called recommended set and transfers information on the recommended set to the MT. The MT selects a subset of the recommended set called active set and undergoes an MBB handoff as explained earlier.

The MT driven MBB procedure works as follows. Here, the BS provides the QoS information of the' neighboring BS along with the neighbor advertisement, NBR_ADV. The MT scans a subset of the neighboring set provided by the BS and selects a subset of the scanned sets, i.e., the active set, and informs the BS of the active set and the preferred target BS. The MT can dissociate from the serving BS and associate with the target BS.
Accordingly this invention relates to a method for maintaining the wireless connectivity and to reduce latency during handoff in wireless multimedia networks, comprising the steps of:
(a) deploying a make before break (MBB) handoff mechanism where a MT measures the carrier-to-interference noise ratio (CINR) from all its associated BSs and chooses the BS with the maximum value of CINR;
(b) advertising the neighboring BS to the MT by the currently serving BS, which then synchronizes and measures the CINR from all neighboring BSs;
(c) choosing a subset of the neighboring BS at which the CINR is above a specified threshold for the application termed the candidate set by the MT; and
(d) selecting a subset of the candidate set called recommended set and informing the MT about the recommended set by the BS, the selection of recommended set form the candidate set being based on CINR measurements considering QoS capabilities.
The other objects, features and advantages of the present invention will be more apparent from the ensuing detailed description of the invention taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1 illustrates a simple wireless network comprising of BS, MS in a cell with CS.
Figure 2 illustrates a handoff procedure in the simple wireless network. It shows signaling between BS#2..N to BS#1 before releasing MSS from BS#1.
Figure 3 illustrates a handoff procedure in wireless network with CS assistance. It also shows the signaling between CS and BS#1 and then release of MSS from BS# 1 to get latched to other BS in the network.
Figure 4 illustrates a simple wireless network handoff procedure with MBB mechanism. It also shows the signaling between the recommended set of BS and BS#1 and subsequently latching MSS to recommended and negotiated BS# and then releasing MSS from BS#1.
Figure 5 illustrates a hand off procedure in simple wireless network with MBB mechanism assisted by CS. It also shows the signaling between CS and BS#1 and MBB of MSS to BS#2 before releasing MSS from BS#1.
Figure 6 illustrates hand off signaling in wireless network. It also shows signaling mechanism between BS#1 and BS# 2..N, before releasing MSS from BS#1.
Figure 7 illustrates CS assisted handoff signaling in wireless network. It shows the signaling involved between CS and BS#1 before releasing MSS from BS#1.
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiments of the present invention will now be explained with reference to the accompanying drawings. It should be understood however that the

disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. The following description and drawings are not to be construed as limiting the invention and numerous specific details are described to provide a thorough understanding of the present invention, as the basis for the claims and as a basis for teaching one skilled in the art how to make and/or use the invention. However in certain instances, well-known or conventional details are not described in order not to unnecessarily obscure the present invention in detail.
In many types of wireless networks, IP packets are segmented to MAC packets before they are transmitted over the air by the BS towards MT. Each flow in the network is identified by a unique connection identifier (CID). For the purpose of QoS capability negotiation, we classify flows as follows:
Class C1: For flows such as voice over IP (VoIP) and streaming video that have very stringent requirements over delay bound and jitter. These flows may also specify their required rate.
Class C2: For flows such as web browsing which specify an average delay requirement and a minimum rate requirement.
Class C3: For flows such as FTP which specify only rate requirements.
Class C4: For flows which have no QoS requirements (called best effort flows).
The recommended set determination invented here work as follows. Let flowXJ.kj) be the /' flow of class Ck traffic in cell / at time /. Let flow)2al(kj) be
the number of class Ck flows that arrived in cell / up to time /. In the following mechanisms, we propose means of selecting the recommended set for the MTs from the candidate set. This is for the mobile driven MBB handoff. For the network driven MBB handoff, the same mechanisms can be adopted to generate recommended sets from the candidate sets.

MECHANISMS TO SELECT THE RECOMMENDED SET
Mechanism I: For class C1 flows
Class C1 flows have requirements of delay bound, jitter and rate. For example, for MPEG-4 and VoIP flows, it is necessary that the flows suffer a maximum delay of no more than a specified bound, e.g., no more than 150 ms for MPEG-4 flows and 60 ms for VoIP flows. Flows of these types also should not experience a delay jitter of more than 1ms. MPEG-4 flows require an average throughput of 384 kbps and VoIP flows require an average throughput of about 10 kbps. When a handoff is to be made and the MS has class C1 flows, then the MS chooses the AP which provides all the above mentioned QoS to these flows. However, in wireless networks, guaranteed QoS cannot be provided due to time varying nature of the wireless channel. Therefore, statistical QoS guarantees need to be provided. When the candidate set is determined by the MS and presented to the BS, the BS obtains parameters like the percentage or fraction of flows in the candidate BS that suffered a violation of each of the above mentioned QoS, i.e., the fraction of class C1 flows that suffered a delay greater than the value specified by the delay bound, the fraction of the flows that suffered a jitter of more than 1ms and the fraction of flows that obtained a throughput less than the required value. From these values the recommended set is chosen to be the ones in which the fraction of flows that violated the requirements is below a specified threshold. However, satisfying all the QoS requirements specified above could not be possible in many cases. In such cases, the recommended set is chosen to be those BS in which the delay bound violation alone is below a specified threshold.
Let d)^liiul be the maximum delay that can be tolerated by flows belonging to class Ck, and let d{*lr be the maximum delay jitter that can be tolerated by flows

belonging to class Ck. It is noted that in this case, k = 1. However, the proposed invention is valid for any class of service which has similar requirements.
Let at each base station BS,, the number of class Ck flows up to time / that suffered
a delay greater than d)*lml be flow{tl!/llv lw/(//rt/(*,/) , and the number of class Ck flows
up to time t that suffered a delay jitter than dl^ler be flow^, viokaeil(kj) . It is
observed that the wireless multimedia network is time variant, and hence the entire statistics of the network till time / may not be useful. Here, by mentioning
flow\2Uiy vloUllcAkj) and flow{;,lr n„w(*,0 , we refer to the statistics at time / starting from a reference time t~t[k) for a pre-specified interval t[k).
Let fl{JJ/tn. vlolalcli(kj) be the fraction of flows up to time / that violated the delay bound and let /?^t,,. Vllthltl.(i(kj) be the fraction of flows up to time / that violated the jitter bound. p[;iy_vmUlu,AkJ) and /?jL_.w,,„/(*.0 are given by

In wireless networks, the QoS guarantees provided are statistical, e.g., it is desired to provide a delay bound violation of less than 5 % for MPEG-n traffic, i.e., less than 5 % of the MPEG-n flows suffer a delay greater than the value specified by the delay bound. In general for class*, it is desired that the fraction of flows violating the delay


Similarly the class C1 type flows have a rate requirement. Let Rate{^tllurvit(j,k) be the average rate required by the /' flow in cell /, and let the j"' flow belong to class Ck. Let Rate^l^AJ^k) be the average rate assigned to the jlh flow of class Ck in cell /.
Let J{,)(t) be the total number of flows scheduled by base station BSt up to time /. Define


Mechanism II: For class C2 and class C3 flows
Class C2 flows are those that have average delay and rate requirements, e.g., web browsing and HTTP. For example, less than 2% of HTTP users must suffer a mean delay of more than 1s per page. Similarly, Class C3 flows specify a rate requirement, e.g.,FTP. For example, less than 2% of FTP users should obtain an average rate (throughput) of less than 9600 bps. The recommended set is chosen to be the set of BS in which the fraction of C2 flows that violate the mean delay and rate requirements is below a specified threshold and the fraction of C3 flows that violate the rate requirements is below a specified threshold.

Class C3 flows are those that have rate requirements, e.g., FTP. For these flows the recommended set can be the Recommendedralc as defined in Mechanism I.
Mechanism III: Based on Network Load
To satisfy the QoS requirements, it is also necessary to take into account the network load conditions at each of the candidate BS. This is given by a number of

flows of each class that entered the network. The MS would like to choose the least loaded BS or the BS in which the load is below a specified threshold. The reason for using this parameter is that, if most of the BS resources are used in servicing flows of class C1, then the probability of the C1 flow at the MS meeting the QoS requirements at the candidate BS decreases.

The network load could be defined either based on the fraction of the total flows that belong to class Ck or the number of flows belonging to class Ck. It is noted that class C1 flows have more stringent requirements on QoS than class C2, which in turn, has more requirements than class C3. Hence, C1 flows need to be given higher priority than C2, which, in turn, needs to be assigned higher priority than C3. We denote this as C1 > C2 > C3>C4. (C4 is given least priority since it is a flow best effort type of traffic).
For each class Ck', it is necessary to have a threshold on the number of Ck flows that can be admitted in a network to provide a statistical QoS guarantee to class Ck' flows.



Mechanism IV: Based on service opportunities
The QoS violation probability can also be determined from the fraction of time spent by the network in servicing flows of each class. This is also called service opportunity to each class. The MS would like to choose the least loaded BS or the BS in which the service opportunity for real time flows is below a specified threshold. The reason for using this parameter is that, if most of the service opportunities provided by the are for servicing flows of class C1, then the probability of the C1 flow at the MS meeting the QoS requirements at the candidate BS decreases.



Mechanism V: Based on network load and service opportunities
The QoS violation can also be obtained from the combination of both Mechanism IV as well as Mechanism V. The MS would like to choose the least loaded BS or the BS in which the both the load as well as the service opportunity is below a specified threshold.

Mechanisms to Select the Active Set
Mechanism VI: Best throughput characteristics
Once the BS lists the recommended set to the MS, the MS could choose the BS with good CINR conditions. However, the MS would also like to receive large throughput. Hence, the MS needs to obtain the maximum throughput at which it can receive data from each of the recommended BS by making use of the channel conditions (CINR) and the obtained throughput before handoff. Hence, a weighted moving average throughput is measured and the MS chooses those recommended BS which have a weighted moving average throughput above a particular threshold. The thresholds for flows depend on the class of the flows.
From the recommended set, the MT could choose the active sets based on CINR measurements. From the measured CINR from BSj} each MT can calculate


Mechanism VII: Least Idle Nodes
In a cell with large number of MS in the idle mode, there are resources that may be available for the MS that undergoes handoff, however, there is a larger probability of other MS contending for the same resources at a later instant of time because of the idle nodes becoming active. Hence, the MS chooses the BS with the least number of idle nodes.
Each mobile node or MT in a cell could be in one of three modes:
• Active mode: When there are active flows to and from the MT
• Sleep mode: When there is traffic with long periods of inactivity during which control overheads can be reduced to improve the efficiency and power saving can be done
• Idle mode: When the mobile does not have any active flow and the air
interface access is denied for the sake of power and control efficiency.

From the active set determined from Mechanism VI, the MT selects the target BS to be the one with the least number of idle nodes.
The signalling messages between the CS, BS and the MT for network driven handover, without and with the assistance of the CS for the proposed Mechanisms I-VI are shown in Figures 6 and 7, respectively. Here, FLO_PRM_REQ is the request for the QoS parameters in each BS. DEL_VIOL is the statistic on the flows that violated delay constraints, JIT_VIOL is the statistic on jitter violation, RATE_VIOL is the statistic on rate violation, NLD_VIOL is the network load statistics, SOP_VIOL is the service opportunity statistics, and IDL_ST is the number of nodes in idle mode.
The signalling messages for MS driven handover for the proposed mechanisms l-VI are shown in Figure 8. Here, in the NBR_ADV, the BS advertises not only the neighboring set, but also the associated parameters like DEL_VIOL, JIT_VIOL, RATE^VIOL, NLD_VIOL, SOP_VIOL and IDLEST. The MS can scan a subset of the neighboring set and compute the DRC and CINR. The MS then returns an active set to the BS and also indicates the target BS. The handover is then made to the target BS.
The change in the IEEE 802.16e standard for incorporating mobile driven HO is given in Figure 9. Here, in the TLV specific TLV encoded information shall be of a nested type containing policy objects. The policy objects could contain information on the network conditions (e.g., NLD_VIOL, SOP_VIOL) and traffic behavior and characteristics (e.g., JIT_VIOL, DEL_VIOL and RATE_VIOL). This information could be used by the MS to determine the subset of neighboring BS which they would scan and thus determine the active set. The capability of the MS to undergo a type 2 handover can be made known to the BS at the time of network entry and initialization from the mobile station basic capability request SBC_REQ and mobile station basic capability response SBC-RSP messages.
The above-presented description is of the best mode contemplated for carrying out the present invention. The manner and process of making and using it is in such a

full, clear, concise and exact terms as to enable to any person skilled in the art to which it pertains to make and use this invention. New embodiments in particular, which also lie within the scope of the invention can be created, in which different details of the different examples can in a purposeful way be combined with one another.
This invention is however, susceptible to modifications and alternate constructions from that disclosed above which are fully equivalent. Consequently, it is not the intention to limit this invention to the particular embodiment disclosed. On the contrary, the intention is to cover all modifications and alternate constructions coming within the spirit and scope of the invention as generally expressed by the following claims which particularly point out and distinctly claim the subject matter of the invention.

GLOSSARY OF TERMS AND THEIR DEFINITIONS
BS: Base station, It is a node with which the MS is communicating.
BS#1 : Base station number one.
Candidate Set: Set of base stations whose signal is detected by MS and its CINR is
above threshold level.
Recommended set: It is set of BS# which is approved for possible latching with
mobile terminal.
CS: Control server.
MAC: Medium Access control (protocol).
CID: Connection identifier.
CL : convergence sub-layer.
CINR: Carrier-to-interference noise ratio
MS/MSS/MT: Mobile station or mobile device or mobile terminal.
RN: Radio network consisting of BSC and BTS. We use it interchangeably with BS
(base station).
BSC: Base Station Catalyst
BTS: Base Transceiver System.
MBB: Make before break. When mobile handoff take place between one BS # to
other BS#.
NBR_ADV: Neighbor Advertisement. It gives the neighboring set to the MS.
SCN__REQ: Scan Request. It is the scan request which the MS issues to the
currently serving BS, i.e., BS #1.
SCN_RSP: Scan Response. Usually (say MS latched to BS#1) BS #1 responds with
a scan response after MS request for SCN_REQ.
SBC_REQ: Mobile station basic capability request
SBC_RSP: Mobile station basic capability response
HO_PRN: Handoff Prenotification. The MS scans all the neighboring BS and gives a
candidate set to BS #1. Then BS #1 issues a handoff prenotification HO_PRN to all
the BS in the candidate set to obtains their QoS capabilities.
HO_PRN_RSP : Handoff Prenotification Response. Once candidates BS receive
Through HO_PRN, they respond with a HO_PRN_RSP providing them their
respective QoS capabilities to BS which is then forwarded to the MS to which it is
latched.

DRC[t,j]: Maximum rate at which MT can receive Data from recommended base
station BSj at time instance t
FLO_PRM_REQ: Request for the QoS Parameters.
DEL_VIOL: Delay violation statistics.
JIT_VIOL: Jitter violation statistics.
RATE_VIOL: Average rate violation statistics.
NLD__VIOL: Network load statistics.
SOP_VIOL: Service opportunity statistics.
IDL_ST: Nodes in Idle mode.
1



WE CLAIM
1. A method for maintaining the wireless connectivity and to reduce latency during
handoff in wireless multimedia networks, comprising the steps of:
(e) deploying a make before break (MBB) handoff mechanism where a MT measures the carrier-to-interference noise ratio (CINR) from all its associated BSs and chooses the BS with the maximum value of CINR;
(f) advertising the neighboring BS to the MT by the currently serving BS, which then synchronizes and measures the CINR from all neighboring BSs;
(g) choosing a subset of the neighboring BS at which the CINR is above a specified threshold for the application termed the candidate set by the MT; and
(h) selecting a subset of the candidate set called recommended set and informing the MT about the recommended set by the BS, the selection of recommended set form the candidate set being based on CINR measurements considering QoS capabilities.
2. A method as claimed in claim 1, wherein MT driven handoff is provided and the BS informs the QoS capabilities of the neighboring set of the BS in the neighborhood advertisement NBR_ADV, from which the mobile computes the active set and the target BS.
3. A method as claimed in claim 1, wherein the recommended set is computed as
Re commended _ set = Rs commended dt,lav^Rt commended jit(crC\RQ commended nUc .
4. A method as claimed in claim 1, wherein the recommended set is computed as
RQ commended _set ~ Recommended nmm (/[,,,7),f|Recommendedralc ,
5. A method as claimed in claim 1, wherein recommended set is determined
as Re commended _set = ^)RQcommended{k) .
k

6. A method as claimed in claim 1, wherein the recommended set is determined as
Recommended set = C^Recommended{k) or
k
Recommended set - ^Recommended^^ .
k
7. A method as claimed in claim 1, wherein the recommended set is obtained as Recommended set = Recommended_seti4)^Recommended_set{5) .
8. A method as claimed in claim 1 wherein for a recommended set RecommendedU) to cell/, the active set is determined as
Active{k) ^{ie Recommended{l) \rj{'\k,t)> p{k)} the serving BS is then selected
either as the cell from the active set with the largest value of rji0(kj) or from any of the active cells at random.
9. A method for handoff in wireless networks comprising the steps of:
(a) responding with a scan response SCN_RSP by the BS#1;
(b) scanning the neighboring set of BS and responds with a candidate set by the MS;
(c) obtaining the QoS capabilities of the neighboring BS and chooses a recommended set for the MS by the BS;
(d) picking one of the BS from the recommended set and undergoing a make before break handoff to the chosen BS (e.g., BS #2) by the MS, and
(e) then the MS dissociating with BS #1
wherein NBR__ADV is the neighbor advertisement, which gives the neighboring set to the MS and SCN_REQ is the scan request which the MS issues to the currently serving BS,(BS#1).
10. A method as claimed in claim 9, wherein BS corresponds the information to the
MS which negotiates with the neighboring BS and chooses a recommended set
of BS.

11. A method as claimed in claim 9, wherein in the network assisted MBB handoff
procedure the BS selects a subset of the neighboring set called recommended
set and transfers information on the recommended set to the MT and the MT
selects a subset of the recommended set called active set and undergoes an
MBB handoff.
12. A method for handoff in wireless networks wherein NBR_ADV is the neighbor
advertisement, which gives the neighboring set to the MS along with the QoS
capabilities; SCN_REQ is the scan request which the MS issues to the currently
serving BS,(BS #1); BS #1 responds with a scan response SCN_RSP; the MS
scans the neighboring set of BS and computes and responds with an active set
and a target BS.


Documents:

190-che-2004-abstract.pdf

190-che-2004-claims duplicate.pdf

190-che-2004-claims.pdf

190-che-2004-correspondnece-others.pdf

190-che-2004-correspondnece-po.pdf

190-che-2004-description complete duplicate.pdf

190-che-2004-description complete original.pdf

190-che-2004-drawing.pdf

190-che-2004-form 1.pdf

190-che-2004-form 19.pdf

190-che-2004-form 26.pdf


Patent Number 201323
Indian Patent Application Number 190/CHE/2004
PG Journal Number 08/2007
Publication Date 23-Feb-2007
Grant Date 29-Jan-2007
Date of Filing 05-Mar-2004
Name of Patentee M/S. SAMSUNG ELECTRONIC CO. LTD., INDIA SOFTWARE OPERATIONS (SISO)
Applicant Address J.P.TECHNO PARK, 3/1, MILLERS ROAD, BANGALORE 560 052
Inventors:
# Inventor's Name Inventor's Address
1 TANEJA. DR. MUKESH C/O.SAMSUNG ELECTRONIC CO. LTD., INDIA SOFTWARE OPERATIONS (SISO),J.P.TECHNO PARK, 3/1, MILLERS ROAD, BANGALORE 560 052
PCT International Classification Number H04B 7/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA