Title of Invention	EFFICIENT MAC ARCHITECTURE FOR CONSERVING RESOURCES IN WIRELESS NETWORKS
Abstract	In this invention, a new MAC layer state transition system is proposed for WMAN IEEE802.16 d/e. It also proposes methods to effectively use it for end-to-end session management when the connection establishment is requested by a node using IP signaling protocols such as RTSP or SIP. The purpose of this is to provide a mechanism to curtail and manage power and air time resources.

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FIELD OF TECHNOLOGY This invention relates to the field of MAC architecture for conserving resources for wireless networks and especially for wireless metropolitan area networks such as IEEE802.16. More specifically this invention encompasses an efficient MAC architecture for conserving resources in wireless networks. DESCRIPTION OF THE RELATED ART In IEEE802.16e an Idle Mode is proposed for efficient handover mechanisms and saving power. IEEE820.16d proposes only the Active Mode and the Sleep Mode. In Sleep Mode the AP MAC maintains signaling to ensure that it supports always on traffic. But in the Idle mode the MSS listens to the DL from the AP only during specific intervals. In the idle mode always "on" traffic is not supported. Also, the introduction of the Idle Mode require following additional signaling. Signaling for Transition to Idle Mode To support Idle Mode the signals as shown in figure-1 are necessary. These include the request (MobJdl_Req) signal from the MSS and the response signal (Mob_ldl_Rsp) signal from the AP. Here MSS initiates the mode transition. If AP initiates the mode transition to the Idle Mode a similar set of signals, i.e. a request signal and a response signal are exchanged. These signals can be called as APJdl_Req and APJdl_Rsp. The State Machine for IEEE802.16d/e MAC The MAC states for IEEE802.16d/e consist of the active state and the sleep state. On power "on" the MAC state is initialized to the active state. While the MAC is in the active state it also performs the network determination. All traffic and control signaling between the MSS and AP happens in the Active State. MS transits to the Sleep Mode when there is no traffic. At the same time the serving AP continues to support always on service to the MSS. Therefore here the air resources are held even during the Sleep Mode. The Handover mechanism while on sleep mode remains same as the Handover during Active Mode. This is again an inefficient approach. The MAC state machines of the BS and MSS described in the current IEEE 802.16e standard have only AWAKE and SLEEP modes in which the network entities shall always maintain the logical and physical connections. These modes in the MAC state machine in IEEE 802.16e have two major disadvantages as follows. Inefficient usage of air resources When an MSS turns on its power, it operates in the awake mode. After some times passed without any valid user traffic in both Uplink and Downlink, the MSS can switch to the sleep mode. But the BS shall maintain these physical and logical resources to provide an always-on service to the MSS after the MSS succeeds network entry and initialization procedures. When the BS has nothing to send for a reasonable time, they switch to the sleep mode. Short sleep mode intervals and occupation of air resources have been regarded as one of the major problems of the present standard. Although a recent proposal IEEE 802.16e/D 1-2004 has addressed this issue only by extending the sleep interval to 1024 frames, it did not present any suggestions to address the inefficient usage problem of air resources and the power conservation while the MSS operates in sleep mode. Absence of a light handover process In all handover described in the present standard, a MSS should initiate a handover process by sending the MAC message to its current serving BS. The pair of a MSS in sleep mode and its BS usually follows the normal handover procedure, which requires exchanging MAC messages and the network re-initialization procedures since the MSS switches to awake mode before performing a handover process. As per the current IEEE 802.16e standard, in order to reduce the handover overhead, the MSS may ignore the entire handover procedure including the location update procedure. However, without performing the location update procedure or without an appropriate paging algorithm in sleep mode, the network may lose the track of the MSS inadvertently. In addition, since there is no explicit way for the MSS to release CIDs assigned by the old BS in this case, the BS may maintain old CIDs for a ' while and waste the resources in result. In the present invention the MAC finite state machine with Idle Mode is discussed. The two MAC architectures considered are (i) the MAC finite state machine is same at the AP and MSS; (ii) the MSS MAC has only the initial state, active mode and the idle mode whereas the AP MAC has initial state, active mode, sleep mode and the idle mode. The MAC finite state machine at the AP has initial state, active mode, sleep mode and the idle mode. The MAC finite state machine is also proposed when the MSS initiates or receives a multimedia session. The IEEE 802.16d/e drafts for MAC have only Active Mode and the Sleep Mode. In the Active Mode the MSS and AP is available but in the Sleep Mode MSS is unavailable. However in the Sleep Mode the serving AP continue to support the service to the MSS. This leads to use of air resources even in the sleep mode. Moreover while Handoff happens in the Sleep Mode, the handover procedure remains same as in the case of Active Mode. This leads to again inefficient use of resources. On the positive side the Sleep Mode supports fast transition to the Active Mode. In the present invention the notion of Idle Mode has been used and we define the MAC finite state machine. It also considers the conditions for transition from one mode to another. SUMMARY OF THE INVENTION The primary object of the invention is therefore to invent a method for conservation and management of resources in WMAN standard IEEE802.16e for wireless multimedia applications. It is another object of the invention to define the state transitions at the MAC layer finite state machine when an additional idle mode is introduced and implemented both at MS and AP. It is another object of the invention to invent the method for establishing a SIP or RTSP session initiated by the MS or CN. Here it is assumed that the MS and AP finite state machines have the idle mode. It is another object of the invention to define the state transitions at the MAC layer finite state machine when the finite state machines at the AP and MS are different. Here it is assumed that the finite state machine at the MS does not have the sleep mode. It is another object of the invention to consider multiple finite state machines at the MS. Here MS maintains flows with distinct APs at the same time. Depending on the network conditions MS can retain the different flows. Further objects of the invention will be clear from the ensuing description. The present invention relates to the MAC architecture for conserving resources. Here two possible architectures are considered: • The AP MAC and MS MAC as in figure (3) has Idle Mode; • The AP MAC has only Active Mode, Sleep Mode and Idle Mode. The MS MAC has only Active Mode and Sleep Mode as described in figure (8) and figure (9). • The present invention also discusses initiation of SIP session when the MS is in active, idle or sleep mode. The SIP request can be send by the CN or the MS. The cases where the MS is in idle mode, active mode or the sleep mode when the SIP request is made have been considered. • Further the case where an MSS has multiple finite state machines is also discussed. Here MS maintains flows from more than one AP. Here depending on the channel conditions the MS can drop some flows. Accordingly this invention relates to a method for active conservation and management of air time and power resources in wireless multimedia network by the introduction of additional state called as Idle state at the MAC layer of both MS and AP wherein at the MS, transition to the Idle Mode is initiated by a set of request and response signals to the AP; upon entering the Idle Mode, the Mobile releases air resources; it monitors the DL frame from the AP for a duration which is defined as the listening window during which window, the AP informs the MS about buffered data at the AP, Handover process and paging information and the AP signals the MS to transit to the Active Mode during the listening window. Accordingly this invention further relates to a method for implementing enhanced MAC layer with SIP and RTSP when the session establishment requests are made by MS or CN wherein MS is in Active Mode and CN sends a SIP request: then data channel is established with the serving AP; the AR sends the QoS Grant to the AP; the AP sends the QoS grant response to the MS; MS then sends the SIP Response to the server; CN responds by sending SIP Play followed by data transfer. The other objects, features and advantages of the present invention will be apparent from the accompanying drawings and the detailed description as follows: BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS Figure 1 illustrates the signaling between MSS and AP in 802.16d/e network. Figure 2 shows the MAC state diagram for IEEE 802.16 d/e between initial and active state at MS or AP. Figure 3 shows the MAC state diagram with idle mode, initial state and the active state comprising of active mode and sleep mode. Figure 4 shows the proposed MAC state diagram incorporating the mode transitions. The proposed state diagram is similar for AP and MS finite state machine. Figure 5 illustrates a multimedia session between a CN and MS. Here MS MAC is assumed to be in active mode. The session establishment request is made by CN. Figure 6 illustrates a multimedia session between a CN and MS. Here MS MAC is assumed to be in sleep mode. The session establishment request is made by CN. Figure 7 illustrates a multimedia session between CN and MS. Here MS MAC is assumed to be in idle mode. The session establishment request is made by CN. Figure 8 illustrates a multimedia session between MS and the CN. Here MS MAC is assumed to be in idle mode. The session establishment request is made by the user. Figure 9 illustrates a multimedia session between MS and the CN. Here MS MAC is assumed to be in sleep mode. The session establishment request is made by the user. Figure 10 shows a schematic diagram of MAC modes and the admissible mode transitions at the AP MAC for the second architecture. Here we assume that the MAC finite state machine at the AP and the MS are different. MAC state transition is shown at the AP-MAC. Figure 11 shows a schematic diagram of MAC modes and the admissible mode transitions at the MS MAC for the second architecture. MAC state transition is shown at the MS-MAC. Figure 12 shows a schematic diagram of the case where the MS supports two flows from two distinct APs. Here it has a MAC finite state machine at the MS for each flow. Figure 13 shows a schematic diagram of the case where the MS supports two flows from the same AP. Here it has only one MAC finite state machine for both the flows put together. DETAILED DESCRIPTION OF THE INVENTION MAC Modes at the AP and MSS - Architecture-I As defined in the previous section, there are basically two states i.e. initial state and the active state. In the active state there are two possible modes, Active Mode and the Sleep Mode. Here one more mode is introduced called the Idle Mode. In Idle Mode, the air resources are freed and the Handover mechanism can be made efficient. It is assumed that the MSS and AP MACs have Idle Mode. At the MS, transition to the Idle Mode is initiated by a set of request and response signals from the AP or initiated by the MS. Upon entering the Idle Mode the Mobile releases air resources. It monitors the DL frame from the AP for a duration which can be defined as the listening window. During this window the AP can inform the MS about buffered data at the AP, location and paging information. Also, the AP can signal the MS to transit to the Active Mode during the listening window. A schematic diagram of the MAC Modes and the admissible Mode transitions is shown in figure 4. It is assumed that the MAC Modes are same for the AP MAC and the MS MAC. A description of the MAC Modes/States is as follows: (a) Initial State • Power on • Network Initialization (b) Active Mode • Network Entry • Channel Allocation • Support Traffic (c) Sleep Mode • Air Interface present • Traffic not present (d) Idle Mode • Release Air Interface • Observe the DL channel during the listening interval • Perform Idle Handover. Here there is no Network reentry process associated with the Active Mode Handover. Mode Transition at the MS and AP MAC In this section the conditions are given for MAC Mode/State transitions. Here the MAC finite state machine is considered for architecture-l. (a) Upon power "on" the MS/AP MAC is in the Initial State. (b) The conditions for MAC Mode transition from Initial State to the Active Mode at MS MAC (if any one of the following conditions happens): • The UL link buffer at the MS is not empty • The DL link buffer at the MS is not empty, or • The DL link buffer at the AP is not empty The transition from the Initial State to the Active Mode is initiated by one of the above conditions. (c) The conditions for MAC Mode transition from Initial Mode to the Active Mode at AP MAC (if any one of the following conditions happens): • The UL link buffer at the AP is not empty • The DL link buffer at the AP is not empty or • The UL link buffer at the MS is not empty. The transition from the Initial State to the Active Mode is initiated if one of the above conditions happens. (d) The conditions for MAC Mode transition from Active Mode to the Sleep Mode at MS MAC (if all the following conditions happen): . The DL link buffer at the AP is empty for T_j^tive_sieep seconds • The UL link buffer at the MS is empty for T^ctive.sieep seconds • The DL link buffer at the MS is empty for T^ctive sieep seconds The transition here depends on the duration for which the buffers are empty. The duration is set by T^ctive. _Sleep seconds. (e) The conditions for MAC Mode transition from Active Mode to the Sleep Mode at AP MAC (if all the following conditions happen): • The DL link buffer at the AP is empty for T_ActjVe_sieep seconds • The UL link buffer at the AP is empty for T^ctive sieep seconds • The UL link buffer at the MS is empty for T_j\ctive_sieep seconds. it may be noted that the transition here depends on T_JACtive_sieep. (e) Conditions for MAC Mode transition from Sleep Mode to the Idle Mode at AP MAC (if one of the following conditions happen): . AP MAC in sleep Mode for duration greater than T_ sieep idle seconds T_sieep idle seconds indicates the duration for which the AP MAC must be in Sleep Mode before the Sleep Mode to Idle Mode transition takes place. T_sieepidie is calculated based on the following measures: (i) Number of times there was a transition from Sleep Mode to Active Mode (ii) The kind of application that was being served before the Active Mode to the Sleep Mode transition (iii) Predicted possibility of an application which demands a fast transition to the active state. (f) Conditions for MAC Mode transition to the Idle Mode at MS MAC (if one of the following conditions happen): • MS MAC Mode in sleep Mode for duration greater than T_sieep idle • AP MAC Mode transition from Sleep Mode to Idle Mode • MS initiated transition from the Initial Mode to Idle Mode. This depends on specific conditions that need to be defined • MS initiated transition from Active Mode to the Idle Mode. This Mode transition again depends on the specific conditions that need to be defined. T_sieep idle seconds indicates the duration for which the AP MAC must be in Sleep Mode before the Sleep Mode to Idle Mode transition takes place. T_sieepidie is calculated based on the following measures: (i) Number of times there was a transition from Sleep Mode to Active Mode (ii) The kind of application that was being served before the Active Mode to the Sleep Mode transition (iii) Predicted possibility of an application which demands a fast transition to the active state. This is possible in the case of multimedia applications. Suppose there is a live coverage of an event and there is some stoppage for a short period. Here the event can resume at anytime. (g) Conditions for MAC Mode transition: Idle Mode to the Active Mode at the MS MAC (if one of the following conditions happen): • The UL link buffer at the MS has data • The DL link buffer at the MS has data • The DL link buffer at the AP has data Here in the first case it is an MS initiated mode transition. In the second and third cases, it is initiated by the AP. The mode transition happens only after the MS scans the downlink data during the listening interval. (h) The conditions for mode transition from Sleep Mode to the Active Mode (are similar to the conditions for Idle Mode to the Active Mode transition) • The UL link buffer at the MS has data • The DL link buffer at the MS has data • The DL link buffer at the AP has data If one of the above conditions is satisfied, MS/AP MAC transition is initiated. In Sleep Mode always "on" connection is supported. Once in Active Mode the mode transitions follow the conditions for transition from the Active Mode. MAC Mode Transition for Multimedia Sessions Consider the situation where a multimedia server, CN - Correspondent Node, wants to establish a session with the MS. The session establishment between the MS and CN can be done via session level protocols (such as SIP - Session Initiation Protocol, RTSP - Real Time Streaming Protocol). The MS MAC can be in any mode when CN sends the session initiation request. The possibilities are considered where MAC is in the Idle Mode, Active Mode or the Sleep Mode. In another case the MS sends SIP message to CN. Here again when the MS sends the SIP request, the MAC modes can be Active, Sleep or Idle. Case-1 - MS in Active Mode when CN send a SIP request: Following the SIP request, data channel is established between MS and serving AP. This is shown in figure (5). Here the MS MAC is in Active Mode as shown in figure (3). Following the data channel establishment, AP sends QoS related signaling to the AR. The AR sends the QoS Grant to the AP on receiving QoS request. The AP sends the QoS grant response to the MS. Once the MS gets QoS response it sends the SIP Response to the server. CN responds by sending SIP Play followed by data transfer. The case where MS is in Sleep Mode is similar to the Active Mode. The Mode transition is shown in figure(3) and figure(4). Case- II - MS in Sleep Mode when CN sends a SIP request: Following the SIP request, the AP MAC mode changes to Active Mode. The Mode Transitions follow figure (3) and figure (4). Signaling is shown in figure (6). Since Sleep Mode supports always "on" connection the air resources are maintained between the MS and serving AP. The MS MAC mode changes to Active Mode in the next listening interval. Also the data channel is established between the serving AP and MS. Following the data channel establishment, AP sends QoS related signaling to the AR. The AR sends the QoS Grant to the AP on receiving QoS request. The AP sends the QoS grant response to the MS. Once the MS gets QoS response it sends the SIP Response to the server. CN responds by sending SIP Play followed by data transfer. Case-Ill MS in Idle Mode and CN sends a SIP request Consider the case where a SIP request message is send by CN, and the MS MAC is in Idle State. Here the MS MAC transits from Idle Mode to Active Mode as shown in figure(3) and figure(4). The condition for MAC mode transition from Idle Mode to Active Mode is discussed in case (d) (the mode transition discussion). On receiving the SIP request, the AP MAC transits from the Idle Mode to Active Mode. The MS MAC responds to the DL only during the listening intervals. Therefore the AP sends signal to MS indicating buffered data and SIP indication during the listening interval. The MS MAC transits to the active state and establishes air connection with the AP. Air connection establishment signal is send to the CN. Upon receiving the AR QoS grant response, the MS sends the SIP response establishing data connection with the CN. Figure(7) describes the signaling when the MS is in Idle Mode and it receives a SIP request. Case- IV MS in Idle Mode and MS sends a SIP request to CN Here a situation is considered where a mobile application initiates a SIP session while it is in Idle Mode. The MAC transition from the Idle Mode to the Initial Mode happens as shown in figure (3) and figure (4). The MS initializes the network and enters the network choosing the best AP. The connection established is only to control traffic. Then it sends SIP request to CN and waits for response. Once the MS receives the SIP response, it establishes data connection and responds with SIP play establishing an IP session with CN. The signaling is shown in figure (8). Case- V - MS in Sleep Mode and MS sends a SIP request to CN Here a situation is considered where a mobile application initiates a SIP session while it is in Sleep Mode. The MAC transition from the Sleep Mode to the Initial Mode happens as shown in figure (3) and figure (4). While the MS is in Sleep Mode it maintains air resources. This situation is different from the case where MS was in Idle Mode and had to perform network reentry. The MS sends SIP request to CN and waits for response. Once the MS receives the SIP response, it establishes data connection and responds with SIP play establishing an IP session with CN. The signaling is shown in figure (9). Proposed MAC Modes at AP and MAC - Architecture-ll Here consider the MAC architecture where the MAC finite state machine is different at the MS and AP. The distinctive feature is that the MS MAC has only Idle Mode. The AP MAC supports both Idle and Sleep Modes. While in Idle Mode the air resources are not maintained, the Handover process can also be efficient. The MAC Modes in at the AP MAC are: (a) Initial State (b) Active Mode (c) Sleep Mode (d) Idle Mode The MAC Modes in at the MS MAC are: (a) Initial State (b) Active Mode (c) Idle Mode Here MAC Modes are assumed to be different at the MSS and the AP. The MAC Modes at the AP MAC are defined as follows: (h) Initial State • Power on • Network Initialization (i) Active Mode • Network Entry • Channel Allocation • Support Traffic (j) Sleep Mode • Air Interface present • Traffic not present (k) Idle Mode • Release Air Interface • Observe the DL channel during the listening interval Mode Transition at the MS and AP MAC (a) Upon power "on" the MAC Mode at the MS/AP is the Initial State. (b) The conditions for MAC Mode transition: Initial State to the Active Mode at MS MAC (if one of the following happens): • The UL link buffer at the MS is not empty • The DL link buffer at the MS is not empty or • The DL link buffer at the AP is not empty. This transition takes place as soon as one of the above events happens. (c) The conditions for MAC Mode transition: Initial Mode to the Active Mode at AP MAC (if one of the following conditions happens): • The UL link buffer at the AP is not empty • The DL link buffer at the AP is not empty, or • The UL link buffer at the MS is not empty. Here again transition follows one of the events above. (d) The conditions for MAC Mode transition: Active Mode to the Idle Mode at MS MAC (if all the following conditions happen): • The DL link buffer at the AP is empty for T^ctivejdie seconds • The UL link buffer at the MS is empty for T^ctivejdie seconds • The DL link buffer at the MS is empty for T_jvctivejdie seconds Here there is no sleep state. Therefore the only possibility if one of the above conditions happens for MS mode to change to Idle. (e) The conditions for MAC Mode transition: Active Mode to the Sleep Mode at AP MAC (if all the following conditions happen): • The DL link buffer at the AP is empty for T_ACtive_sieep seconds • The UL link buffer at the AP is empty for T^ctive.sieep seconds • The UL link buffer at the MS is empty for T_Active_sieep seconds. It is possible for AP MAC to be in Active Mode when MS MAC is in Idle Mode. This happens when the AP MAC DL buffer is empty and only the UL buffer at the AP has data. (I) Conditions for MAC Mode transition: Sleep Mode to the Idle Mode at AP MAC (if one of the following conditions happen): • AP MAC Mode in sleep Mode for duration greater than T_ AP_MAC_Sleep_Max • MS MAC in Idle Mode and the MAC UL and DL buffer empty then the AP MAC can go the Idle Mode directly. (m) Conditions for MAC Mode transition: Idle Mode to the Active Mode at the AP MAC (if one of the following conditions happen): • The DL link buffer at the AP has data • The UL link buffer at the AP has data • The UL link buffer at the MS has data The Mode transition from Sleep Mode to the Active Mode follows the condition for Idle Mode to Sleep Modes at the AP MAC. Another possibility is when the BS MAC goes to the Initial Mode from the Sleep Mode or the Idle Mode. This is possible if there is a MS initiated SIP request and the MS is in Idle mode. Multiple Finite State Machine at MS MAC Consider the MAC architecture where the MS MAC maintains flows from different APs and each flow has an associated finite state machine. This situation is shown in figure (12). This architecture is useful in the following situations: • Efficient Handover. The MS maintains connection with more than one AP from a set and if the current serving AP hands over to another AP in the set it can initiate an efficient handover. • Can drop flows depending on the network conditions. For example if the CINR drops below a threshold for a particular then MS can drop the flow. Also if the QoS associated with one flow drops resources can be allocated dynamically to other flows. Consider the MS MAC finite state machine. In the first case it is assumed that all the finite state machines are shown in figure (3). The modes are • Initial State • Active Mode • Sleep Mode • Idle Mode Consider figure (12). Here it is assumed that there are two flows associated to two different APs. We have a separate MS MAC finite state machine associated to each flow. Consider the following situations: • AP1 MAC is in Idle Mode and AP2 MAC is in Active Mode. The MS MAC finite state machine associated with the AP1 is therefore in Idle Mode and the MS MAC finite state machine associated with AP2 MAC will be in active mode. Here all resources can be allocated to the flow associated with the AP2. • AP1 MAC is in Idle Mode and AP2 MAC is also in Idle Mode. The MS MAC finite state machine associated with the AP1 is therefore in Idle Mode and the MS MAC finite state machine associated with AP2 MAC will also be in Idle Mode. • Consider the case where MS is maintaining flows from AP1 and AP2. Here it is assumed that AP1 is the serving AP. Suppose the CINR of the flows from AP1 falls below a minimum level. Here MS can handover to AP2. Here the state transitions associated with individual MAC finite state machines is same as the what is shown in figure(4) and cases(a) to case(g) associated with the Architecture-I. Consider figure (13). Here it is assumed a situation where MS listens to more than one flow from the same AP. The MAC architecture is considered where there is only one finite state machine associated with both the flows. This is useful in the following situations: • Depending on the CINR/QoS associated with each flow the MAC dynamically allocates resources to the other flow. • If the traffic associated with one flow is not present for a minimum duration, the MS MAC again allocates resources for the other flow which is present. • If the traffic associated with both the flows is not present for a minimum duration then MS MAC finite state machine transits to the sleep or idle (this depends on cases(a) to case(g) above. Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be affected therein by one skilled in the art without departing from the scope or spirit of the invention. Glossary of Terms: AP: Access Point AR; Access Router CN: Correspondent Node DL: Down Link MS: Mobile Station SIP: Session Initiation Protocol RTSP: Real Time Streaming Protocol We Claim 1) A method for active conservation and management of air time and power resources in wireless multimedia network wherein at the MS, transition to the Idle Mode is initiated by a set of request and response signals to the AP; and upon entering the Idle Mode, the Mobile releases air resources; it monitors the DL frame from the AP for a duration which is defined as the listening window during which window, the AP informs the MS about buffered data at the AP, Handover process and paging information and the AP signals the MS to transit to the Active Mode during the listening window. 2) The MAC architecture for conserving resources wherein the AP MAC and MS MAC has Idle Mode. 3) MAC Architecture as claimed in claim 2, wherein the AP MAC has Active Mode, Sleep Mode and Idle Mode and the MS MAC has only Active Mode and Sleep Mode. 4) The method for implementing enhanced MAC layer with SIP and RTSP when the session establishment requests are made by MS or CN wherein MS is in Active Mode and CN sends a SIP request: then data channel is established with the serving AP; the AR sends the QoS Grant to the AP; the AP sends the QoS grant response to the MS; MS then sends the SIP Response to the server; CN responds by sending SIP Play followed by data transfer. 5) A method as claimed in claim 4, wherein a SIP request message is send by CN; the MS MAC transits from Idle Mode to Active Mode; On receiving the SIP request the AP MAC transits from the Idle Mode to Active Mode; the MS MAC responds to the DL only during the listening intervals; the AP sends signal to MS indicating buffered data and SIP indication; during the listening interval the MS MAC transits to the active state and establishes air connection with the AP; Air connection establishment signal is send to the CN; upon receiving the AR QoS grant response, the MS sends the SIP response establishing data connection with the CN. 6) A method as claimed in claim 4, wherein a SIP request message is send by CN; the MS MAC transits from Sleep Mode to Active Mode; On receiving the SIP request the AP MAC transits from the Idle Mode to Active Mode; the MS MAC responds to the DL only during the listening intervals; the AP sends signal to MS indicating buffered data and SIP indication; during the listening interval the MS MAC transits to the active state; upon receiving the AR QoS grant response, the MS sends the SIP response establishing data connection with the CN. 7) A method as claimed in claim 4, wherein a mobile application initiates a SIP session while it is in Idle Mode; the MAC transits from the Idle Mode to the Initial Mode; the MS initializes the network and enters the network choosing the best AP; the connection established is for control traffic; then it sends SIP request to CN and waits for response; Once the MS receives the SIP response, it establishes data connection and responds with SIP play establishing an IP session with CN. 8) A method as claimed in claim 4, wherein a mobile application initiates a SIP session while it is in Sleep Mode; the MAC transits from the Idle Mode to the Active Mode; then it sends SIP request to CN and waits for response; Once the MS receives the SIP response, it establishes data connection and responds with SIP play establishing an IP session with CN. 9) MAC architecture for efficient handover and dynamic load balancing among several flows comprising multiple finite state machines at the MS MAC wherein each finite state machine maintains one flow from different Aps. 10) MAC architecture as claimed in claim 1, wherein the resources are allotted depending on the QoS class of each flow comprising a single finite state machine at the MS MAC for maintaining more than one flow from the same AP. 11) A method for active conservation and management of air time and power resources in wireless multimedia network by the introduction of additional state called as Idle state at the MAC layer of both MS and AP substantially as herein described particularly with reference to the drawings.

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0191-che-2004 abstract-duplicate.pdf

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0191-che-2004 description (complete)-duplicate.pdf

0191-che-2004 drawings-duplicate.pdf

0191-che-2004 form-13.pdf

191-che-2004 form 2.pdf

191-che-2004-abstract.pdf

191-che-2004-claims.pdf

191-che-2004-correspondnece-others.pdf

191-che-2004-correspondnece-po.pdf

191-che-2004-description(complete).pdf

191-che-2004-drawings.pdf

191-che-2004-form 1.pdf

191-che-2004-form 19.pdf

191-che-2004-form 26.pdf