KR20080075144A - Flexible multicast and/or broadcast listening intervals - Google Patents

Abstract

The present invention provides a new and unique method and apparatus for communicating information between two nodes, points or terminals in a wireless local area network (WLAN), where a variable multicast and/or broadcast listening interval and associated signalling is allowed between the two nodes, points or terminals in the wireless LAN network. The two nodes, points or terminals include an access point (AP) or other suitable network node or terminal and a station (STA) or other suitable network node or terminal in the WLAN. The AP and the STA can indicate its capability to support a flexible multicast and broadcast listening interval by using new fields in Beacon and Probe Response frames and in (Re)Association Request Frames. The multicast and broadcast service is setup by using Multicast and Broadcast Service Setup signalling.

Description

Flexible multicast and / or broadcast listening intervals

Cross-Reference to the Related Application

This application claims priority to Provisional Application No. 60 / 733,739, filed November 4, 2005, which is incorporated herein by reference in its entirety.

The present invention relates to a method and apparatus for providing multicast and / or broadcast service optimization in a wireless LAN network, comprising the method described in IEEE 802.11.

A problem with current multicast service schemes in IEEE 802.11 networks is related to the power save function. The basic standard defines that a fixed power save scheme is used by broadcast and different multicast services. This technique basically defines a fixed listening interval for the non-AP STA. The AP buffers all broadcast and multicast traffic, and after a certain DTIM beacon frame (DTIM is every nth beacon frame), the AP automatically forwards all buffered broadcast and multicast traffic. This problem is that different broadcast and multicast services can have very different service characteristics and having only one static scheme at the WLAN level is not flexible enough. Services come from very basic IP level broadcast services such as Address Resolution Protocol (ARP) or Dynamic Host Configuration Protocol (DHCP) (which typically have low bit rates with relaxed delay constraints). , Different multicast streaming services (audio, video) with higher bit rate constraints and tighter real-time constraints.

Indeed, using the WLAN multicast service extension, there may be different services: others such as ARP create IP connectivity for the terminal. These protocols always run in the background. If the terminal is not activated, i.e. in the standby state, the power consumption for receiving data from this protocol defines the standby power consumption. These protocols require long multicast / broadcast listening intervals to reduce activity periods and power consumption. Some applications, such as audio and video services, require short multicast listening intervals to meet QoS and delay constraints.

Nowadays, the AP may indicate that there is broadcast or multicast data buffered using the same single bit. This causes the terminal to listen to multicast data even if they do not receive anything.

In the broadest sense, the present invention provides a novel and unique method and apparatus for communicating information between two nodes, points or terminals in a wireless local area network (WLAN), wherein the two nodes in the wireless LAN network. Variable multicast and / or broadcast listening intervals and associated signaling between points or terminals are allowed.

The two nodes, points or terminals are characterized in that they comprise an access point (AP) or other suitable network node or terminal in a WLAN and a station (STA) or other suitable network node or terminal.

In the operating state, the AP and the STA may perform variable multi by using a field defined in a beacon and probe response frame and a (re) association request frame of the present invention. And its ability to support cast and broadcast listening intervals. The multicast and broadcast service may be configured by multicast and broadcast service setup signaling.

Indeed, the present invention allows for the use of variable multicast and broadcast listening intervals at the MAC level. One aspect of the present invention is a signaling technique that can be used to set the corresponding listening interval per multicast group. According to some embodiments of the present invention, broadcast traffic will be transmitted using a legacy DTIM interval, but the DTIM interval can be set to be relatively long because typically it has a more stringent request condition. This is because it no longer needs to support different multicast services.

The invention also includes a mechanism that allows the AP to advertise active multicast and broadcast services within the BSS.

The present invention also includes a mechanism for individually indicating whether there is buffered broadcast traffic or buffered multicast traffic (per each multicast group (address)) within the AP.

Overall, the present invention provides a means for improving the performance of broadcast and multicast services within an IEEE 802.11 network, the effect of which is:

Setting the DTIM interval to be relatively long,

Advertisement operation of the multicast service by the AP, and

By performing an operation for indicating each multicast group whether there is a buffered broadcast / multicast traffic in the AP.

Furthermore, beacon and probe responses may be used to advertise an active listening interval by using the multicast service information element therein, as described in related provisional application number 60 / 733,999 as described in docking number WFVA / Nokia. As described in connection with the IEEE P802.11 section in 944-4.59 / NC46867, which provides an indication for buffered broadcast / multicast data in the AP (Buffered Traffic Indicator, Buffered Traffic Indication). ).

The drawings include the accompanying drawings, which are not necessarily drawn to scale.

1A illustrates an IEEE 802.11 WLAN system in accordance with some embodiments of the present invention.

1B illustrates the basic steps of a method according to some embodiments of the invention.

2 illustrates an access point (AP) in accordance with some embodiments of the present invention.

3 illustrates a station (STA) in accordance with some embodiments of the present invention.

4A and 4B show a block diagram of a Universal Mobile Telecommunications System (UMTS) packet network architecture in accordance with some embodiments of the present invention.

1A illustratively illustrates an IEEE 802.11 WLAN system, generally indicated at 2, which communicates with mobile and secondary devices such as personal digital assistants (PDAs) 3, laptops 4 and printers 5, and the like. Provide communication between devices. The WLAN system may be connected to a wired LAN system that provides a connection to a wireless device or the Internet for accessing information and files stored on a file server or other suitable device. These devices can communicate directly with each other without the need for base stations in a so-called "ad-hoc" network, or they can communicate through a base station called an access point (AP) in IEEE 802.11 terminology. As indicated by 6 and shown, local distributed services (DS) or broadband extension services are used to provide distributed services through the AP. In a WLAN system, end user access devices are known as communication stations (STAs), which convert wireless signals into digital signals that can be routed to or from the communication device and receive the data packets from other communication devices and / or Or transceivers (transmitters / receivers) capable of connecting to access points (APs) distributed over a network. STAs range from a wireless network interface card (NIC) adapter connected to a device to any integrated wireless module known in the art that may be part of the device and may be an external adapter (USB), PCMCIA card, or USB dongle (embedded). It can have various forms.

The present invention provides a novel and unique method and apparatus for communicating information between two nodes, STAs, points or terminals within a wireless local area network (WLAN) shown in FIG. Variable multicast and / or broadcast listening intervals and associated signaling between the nodes, STAs, points or terminals are allowed. 1B shows the basic steps 7 and 8 of the method according to some embodiments of the invention.

The two nodes, STAs, points or terminals in the WLAN may include an access point (AP) or other suitable network node or terminal 10 shown in FIG. 2 or a communication station (STA) or other suitable network node or terminal (shown in FIG. 3). 20), which operates in a wireless LAN network consistent with that shown in FIG. 1A. The AP 10 and the STA 20 have corresponding modules 12, 22 configured to allow variable multicast listening intervals and related signaling between two nodes, points or terminals in the wireless LAN network. In practice, this technique allows negotiation for multicast and broadcast type data modes.

Basic implementation

Basic configuration and cooperation of the AP 10 and the STA 20 according to some embodiments of the present invention may include the following description.

APs and STAs use their new fields in the Beacon and Probe Response frame and in the (Re) Association Request Frame to make their variable multicast and broadcast listening intervals. Has the ability to indicate support ability. For example, these new fields are as described in Provisional Application No. 60 / 733,999, filed Nov. 4, 2005, which is incorporated herein by reference in its entirety and incorporates Radio Resource Management capabilities. Corresponds to the IEEE 802.11 section relating to Management Capabilities. The technical scope of the present invention is not limited to the use of new fields in the beacon and probe response frames and (re) join request frames of the aforementioned applications. For example, embodiments of the present invention and the technical scope of the present invention are envisioned and intended to include the use of other types of fields in beacon and probe response frames and (re) join request frames, now known or in the future. do.

Multicast and broadcast services may be established using multicast and broadcast service configuration signaling. During this signaling phase, the listening interval for the corresponding multicast and broadcast service can be agreed. The STA may suggest a listening interval based on the multicast and broadcast service characteristics, and the AP may accept the proposal or define a new listening interval. The same listening interval should be used for all terminals receiving the same multicast and broadcast transmissions. For example, the multicast service setup is described in the content corresponding to the IEEE 802.11 section related to the frame format of provisional application number 60 / 733,999 described above. However, the technical scope of the present invention is not limited to using the multicast service configuration described herein. For example, embodiments of the present invention The technical scope of the present invention is envisioned and intended to include using other types of multicast service configurations that are now known or will be developed in the future.

In addition, the AP may advertise the activated listening interval by sending a Multicast Service Info information element within each beacon and probe response frame. By way of example, such an information element is described in provisional application number 60 / 733,999, which corresponds to a section of IEEE 802.11, but embodiments of the invention The technical scope of the invention is different from information elements which are now known or will be developed in the future. It is envisioned and intended to include the use of types. By using this element, the AP may also indicate whether there is buffered broadcast data and / or buffered multicast traffic belonging to a particular multicast group. In general, having a Multicast Service Info field in a beacon and probe response can be valuable information for roaming STAs, because what multicast services they have enabled in their BSSs? Because you know immediately.

The novel features of operation during the power save mode are consistent with and form part of the sections of IEEE P802.11, as described below.

Enhanced Multicast and Broadcast Power Management

Using improved multicast and broadcast services in accordance with some embodiments of the present invention, it is possible to create a variable service interval for multicast and broadcast services.

Service intervals for multicast and broadcast services are generated using multicast and broadcast service configuration signaling. A non-AP STA wishing to join a multicast group may suggest a multicast listening interval to the corresponding AP. The multicast and broadcast listening interval may be a multiple of the beacon period, or may be defined as the number of time units (TUs). The duration of the TU is 1024 microseconds. The AP will select the multicast and broadcast listening intervals, which will be assigned to the Multicast and Broadcast Service Setup Response frame, the Multicast Service Mode Change frame, and the beacons and pros. It will be displayed within the Beacon and Probe Response frame.

AP behavior

If a determined multicast service is used in accordance with some embodiments of the present invention, the AP will send a beacon with a complete Multicast Service Info field for every beacon.

Another embodiment of the present invention will take the form of transmitting a complete multicast service information field for every DTIM beacon. In the TIM Beacon, the AP will transmit a multicast service information element that contains information of the multicast service transmitting data after the corresponding TBTT. If multicast data transmissions are scheduled after that TBTT, and no multicast address is listened to in the multicast service information, then no data is sent from that multicast address after TBTT. The multicast service information element transmitted after the TIM Beacon TBTT does not include information of the multicast service transmitting data between TUs. If there is a buffered frame belonging to a particular multicast group, the Buffered Traffic Indication bit will be set.

If an extended multicast and broadcast service is used in accordance with some embodiments of the present invention, then the AP may determine that all multicast frames belonging to a particular multicast group have a service interval defined for that multicast and broadcast service. Will send later. The More Data field in the MAC header of each multicast frame will be set to indicate that there are other buffered multicast MSDUs from that multicast address. If the AP is unable to send all buffered multicast MSDUs before the subsequent TBTT, the AP may indicate by setting the buffered traffic indicator in the multicast service information field to 1 that it will continue to deliver that multicast MSDU. Can be. The buffered traffic indicator will be set to 1 until all buffered multicast frames are transmitted.

Receive Operation for non-AP STAs in Power Save (PS) mode

If extended multicast and broadcast services are used in accordance with some embodiments of the present invention, the non-AP STA will wake up prior to the defined multicast and broadcast listening interval. The non-AP STA may not continue until the More Data field in the multicast MSDU indicates that there are no more buffered multicast MSDUs or the multicast service is no longer listed in the multicast service information field or the buffered traffic indicator field is no longer It will stay awake until it indicates there is no buffered multicast MSDU.

For legacy compatibility reasons, broadcast and multicast traffic may need to be delivered as in the conventional method if the AP is not sure that all relevant STAs can use the extended broadcast / multicast service. . STAs using the extended broadcast / multicast service may need to consider this in order to prevent duplicate frames.

Alternative Implementation

Other implementation options are as follows:

. The AP can acquire the multicast service characteristics by itself and set the listening interval independently without any multicast service configuration signaling.

. Multicast service information may also be transmitted within individual frames. In this way, the overhead in the beacons is reduced. On the other hand, this is undesirable from the point of view of a roaming STA, for example. In addition, from the power save point of view, such information is represented by known intervals, so that the corresponding STA can optimize its sleeping cycle accordingly.

. Instead of using the full multicast MAC address in the signaling phase, a compressed format can be used.

. As described in the present invention, the AP may set a complete multicast service information element to all beacons.

Implementation of the functionality of the modules

The functionality of the aforementioned AP 10 and STA 20 can be implemented within the corresponding modules 12, 22 shown in FIGS. 3 and 4. For example, to also be consistent with what is described herein, the functionality of modules 12 and 22 may be implemented using hardware, software, firmware, or a combination thereof, although the technical scope of the present invention is directed to such specific implementations. It is not intended to be limited to the examples. In a typical software implementation, modules 12 and 22 may include one or more microprocessors, arbitrary read memory (RAM), read only memory (ROM), input / output devices and control, data and address buses that interconnect them, or It may be more than one microprocessor-based architecture. Those skilled in the art will be able to program such microprocessor-based implementations to perform the functionality described herein without undue experimentation. The technical scope of the present invention is not intended to be limited to any particular implementation using techniques that are now known or will be developed in the future. Furthermore, the technical scope of the present invention is intended to include the modules 12, 22 in the form of stand-alone modules as shown or with other circuitry for constructing other modules.

The other modules 14, 24 and their functionality are known in the art and do not constitute an essential part of the present invention and are not described in detail herein. For example, the other module 24 may include other modules that are morphological parts of a typical mobile phone or mobile terminal, such as the UMTS Subscriber Identity Module (USIM) and Mobile Equipment (ME) module, which are known in the art and not described herein. It may include.

The present invention allows for variable listening (sleeping) intervals for multicast services, thus allowing a more optimized power save of the STA; Separating broadcast and multicast services with different indicators for different listening intervals and buffered data, the broadcast multicast service information provides information about ongoing multicast transmissions to roaming STAs, where The information can speed up multicast service setup.

Universal Mobile Telecommunications System (UMTS) Packet Network Architecture

4A and 4B show a block diagram of a Universal Mobile Telecommunications System (UMTS) packet network architecture. In FIG. 4A, the UMTS packet network architecture includes a major component of a user equipment (UE), a UMTS Terrestrial Radio Access Network (UTRAN), and a Core Network (CN). The UE is interfaced to the UTRAN via a wireless (Uu) interface, which is interfaced to the core network (CN) via a wired (Iu) interface. FIG. 4B further illustrates some of the features of this architecture, in particular illustrating the UTRAN, which includes multiple Radio Network Subsystems (RNS), each of which has at least one Radio Network Controller. , RNC). In operation, each RNC may be connected to multiple Node Bs, and the Node Bs may be wirelessly connected to the multiple UEs via the bus bar interface Uu shown in FIG. 4A. A given UE may be wirelessly connected to a multiple Node B even if one or more Node Bs are connected to different RNCs. For example, UE1 of FIG. 4B may be wirelessly connected to Node B2 of RNS1 and Node B3 of RNS2, where Node B2 and Node B3 are adjacent Node Bs. RNCs of different RNSs can be connected by an Iur interface, thus allowing the mobile UE to stay connected with both RNCs while traveling from a cell belonging to Node B of one RNC to a cell belonging to Node B of another RNC. . Integrating the IEEE 802.11 WLAN system of FIG. 1A and the UMTS packet network architecture of FIGS. 4A and 4B yields an STA in the form of a UE, such as a mobile phone or a mobile terminal. The technique of interworking the WLAN (IEEE 802.11) shown in FIG. 1A with other technologies (eg, 3GPP, 3GPP2 or 802.16) as shown in FIGS. 2A and 2B is a protocol specification for 3GPP and 3GPP2. Currently defined at The technical scope of the present invention is intended to include the same implementations related to this UMTS packet network architecture.

Scope of Invention

Thus, the present invention includes implementations of features, combinations of elements, and parts of the components illustrated in the configurations described below.

Therefore, the objects clarified from the above-described objects of the present invention and the above-described detailed description can be efficiently achieved, and it is possible to make specific changes to the above-described configuration without departing from the technical spirit of the present invention. All matters shown in the included or attached drawings are provided for illustrative purposes only and are not intended to limit the invention.

The present invention can be used to implement the disclosure described in IEEE 802.11 to provide multicast and / or broadcast service optimization in a wireless LAN network.

Claims (34)

Communicating information between two nodes, points or terminals in a wireless local area network (WLAN); And Allowing a variable multicast and / or broadcast listening interval and associated signaling between the two nodes, points or terminals in the wireless LAN network. The method of claim 1, Wherein the two nodes, points or terminals comprise an access point (AP) or other suitable network node or terminal in a WLAN and a station (STA) or other suitable network node or terminal. The method of claim 2, The AP and STA may support variable multicast and broadcast listening intervals using new fields in a Beacon and Probe Response frame and a (Re) Association Request Frame. Characterized by being able to indicate its ability to do so. The method of claim 1, The multicast service is set by multicast and broadcast service setup signaling. The method of claim 1, wherein during the signaling phase, Wherein the listening interval for multicast and broadcast services can be agreed between the two nodes, points or terminals in the wireless LAN network. The method of claim 2, The STA may propose a listening interval based on the multicast and broadcast service characteristics, Wherein the AP may accept the proposal or define a new listening interval. The method of claim 6, And the AP may also advertise an active listening interval by sending a Multicast Service Info information element within each Beacon and Probe Response frame. The method of claim 7, wherein By using this element, the AP can also indicate whether there is buffered broadcast data and / or buffered traffic indication belonging to a particular multicast group. How to. In a wireless local area network (WLAN), Includes two nodes or points for communicating information with each other, Wherein said node or points comprise modules configured to allow variable multicast and / or broadcast listening intervals and associated signaling between said two nodes, points or terminals in said wireless LAN network. Wireless Local Area Network (WLAN). The method of claim 9, Wherein said two nodes, points or terminals comprise an access point (AP) or other suitable network node or terminal in a WLAN and a communication station (STA) or other suitable network node or terminal. The method of claim 10, The AP and STA may indicate their ability to support variable multicast and broadcast listening intervals using new fields in a beacon and probe response frame and a (re) join request frame. Network (WLAN). The method of claim 9, Multicast and broadcast service is a wireless local area network (WLAN), characterized in that set up by the multicast and broadcast service configuration signaling. The method of claim 9, wherein during the signaling phase, And the listening interval for the multicast and broadcast service can be agreed between the two nodes, points or terminals in the wireless LAN network. The method of claim 10, The STA may propose a listening interval based on the multicast and broadcast service characteristics, The AP can accept the offer or define a new listening interval. The method of claim 14, The AP can also advertise an active listening interval by sending a Multicast Service Info information element within each beacon and probe response frame. The method of claim 15, By using this element, the AP can also indicate whether there is buffered broadcast data and / or buffered traffic indication belonging to a particular multicast group. Wireless Local Area Network (WLAN). In a first node, point or terminal, One or more modules configured to communicate information to a second node, point, or terminal in a wireless local area network (WLAN); And And a module configured to allow variable multicast and / or broadcast listening intervals and associated signaling between the two nodes, points or terminals in the wireless LAN network. The method of claim 17, Wherein said two nodes, points or terminals comprise an access point (AP) or other suitable network node or terminal in a WLAN and a communication station (STA) or other suitable network node or terminal. The method of claim 18, The AP and STA may indicate their ability to support variable multicast and broadcast listening intervals using new fields in a beacon and probe response frame and a (re) join request frame. Node, point or terminal. The method of claim 17, The first node, point or terminal, wherein the multicast and broadcast services are set up by multicast and broadcast service configuration signaling. 18. The method of claim 17, wherein during the signaling phase, And the listening interval for the multicast and broadcast service can be agreed between the two nodes, points or terminals in the wireless LAN network. The method of claim 18, The STA may propose a listening interval based on the multicast and broadcast service characteristics, The AP may accept the offer or define a new listening interval. The method of claim 22, The AP may also advertise an active listening interval by sending a Multicast Service Info information element within each beacon and probe response frame. The method of claim 23, wherein By using this element, the AP can also indicate whether there is buffered broadcast data and / or buffered traffic indication belonging to a particular multicast group. A first node, point or terminal. The method of claim 17, The AP may also advertise an active listening interval by sending a Multicast Service Info information element within each beacon and probe response frame. The method of claim 25, And the second node, point or terminal returns to a power save state using the More Data bit indicator. A computer program product having program code, the program code being stored on a carrier that can be read by a machine such that the computer program is associated with a first node, point or terminal, such as an access point (AP), a communication station (STA). When executed within a module of one of the same second node, point or terminal or a combination thereof, A computer program product for performing the steps of a method comprising allowing a variable multicast and / or broadcast listening interval and associated signaling between two nodes, points or terminals in a wireless local area network (WLAN). . The method of claim 1, Implementing the steps of the method via a computer program running in a processor, controller or other suitable module in one or more network nodes, points or terminals or elements in the wireless LAN network. Way. The method of claim 1, Multicast or broadcast traffic is transmitted using a 'More Data' bit to indicate that the first node, point or terminal contains buffered data from the same multicast or broadcast address. The method of claim 29, And wherein the second node, point or terminal returns to a power save state using the More Data bit indicator. Means for communicating information between two nodes, points, or terminals in a wireless local area network (WLAN); And Means for allowing variable multicast and / or broadcast listening intervals and associated signaling between the two nodes, points or terminals in the wireless LAN network. The method of claim 31, wherein Wherein the two nodes, points or terminals comprise an access point (AP) or other suitable network node or terminal in a WLAN and a communication station (STA) or other suitable network node or terminal. The method of claim 31, wherein And the multicast service is set by multicast and broadcast service configuration signaling. The method of claim 31, wherein during the signaling phase, And the listening interval for the multicast service can be agreed between the two nodes, points or terminals in the wireless LAN network.

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