JP4960372B2 - Multicast and / or broadcast variable waiting period - Google Patents

Description

  The present invention relates to a method and apparatus for optimizing multicast and / or broadcast services in wireless local area networks, including those described in IEEE 802.11.

  A problem with current multicast service schemes in IEEE 802.11 networks is related to the power saving function. The basic standard specifies that various broadcast and multicast services use a fixed power saving scheme. Basically, this scheme defines a fixed listen period for non-AP STAs. The AP buffers all broadcast and multicast information and automatically delivers all buffered broadcast and multicast information after a specific DTIM beacon frame (DTIM is every nth beacon frame) . The problem here is that various broadcast and multicast services can have very different service characteristics, and a single static scheme at the WLAN level is not flexible enough. The service is usually available at high bit rates from very basic IP level broadcast services such as Address Resolution Protocol (ARP) or Dynamic Host Configuration Protocol (DHCP), which are usually low bit rates and loose delay requirements. There are even various multicast stream services (audio, video, etc.) with strict real-time requirements.

  In short, various services are possible by strengthening the WLAN multicast service. Another service, such as ARP, creates an IP connection to the terminal. These protocols always run in the background. When the terminal is inactive, that is, in the standby state, the power consumption for receiving data from these protocols defines the standby power consumption. These protocols require long multicast or broadcast wait periods to reduce active periods and power consumption. Some applications such as audio and video services require a short multicast waiting period to meet QoS and delay requirements.

  The current AP can indicate that broadcast or multicast data is buffered with the same 1 bit. For this reason, even when the terminal does not receive the multicast data, it must wait for the multicast data.

  The present invention, in its broadest sense, provides a new and unique method and apparatus for transmitting information between two nodes, points, or terminals in a wireless local area network (WLAN). Multicast and / or broadcast variable waiting periods and related signal notifications can be made between two nodes, points, or terminals in a wireless local area network.

  The two nodes, points, or terminals include an access point (AP) in the WLAN, other appropriate network node or terminal, and a wireless station (STA), other appropriate network node or terminal. .

  APs and STAs can use the new fields in the beacon and probe response frames and (re) association request frames to indicate the ability to accommodate multicast and broadcast variable waiting periods. The multicast and broadcast service is set by multicast and broadcast service setting signal notification.

  In short, the present invention makes it possible to use multicast and broadcast variable waiting periods at the MAC level. One part of the present invention is a signaling scheme that can be used to set a waiting period for each multicast group. According to some embodiments of the present invention, the broadcast information is transmitted using a conventional DTIM period, but the DTIM period no longer needs to accommodate various multicast services, which usually have strict requirements. Can be set fairly long.

  The present 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 separately indicating whether broadcast information or multicast information is buffered in the AP (for each multicast group (address)).

Overall, the present invention provides a means to achieve better broadcast and multicast service performance in IEEE 802.11 by enabling:
-Set DTIM period fairly long-AP advertises multicast service-Shows for each multicast group whether broadcast information or multicast information is buffered in AP

  Furthermore, the active standby period using the multicast service information element can be advertised using the beacon and the probe response. This is document number WFVA / Nokia 944-4.59 / NC46867 associated with some chapters of IEEE P802.11 which gives instructions on buffered broadcast or multicast data in the AP (buffer information indication). It is described by way of example in identified US Provisional Patent Application No. 60 / 733,999.

  The accompanying drawings are not necessarily drawn to scale.

  FIG. 1a shows an IEEE 802.11 WLAN system, generally designated 2 as an example. The system provides communication between communication devices such as mobile devices and secondary devices including personal digital assistants (PDAs) 3, laptops 4, printers 5, etc. The WLAN system may connect to a wired LAN system, the latter allowing wireless devices to use information and files on a file server or other suitable device and connect to the Internet. These devices can communicate directly with each other via a so-called “ad hoc” network without a base station, as shown, or a base station (referred to as an access point (AP) in 802.11 terminology) (referred to as 6). Via the local distribution service (DS) or the wide area extension service. In a WLAN system, a device to which an end user connects is known as a radio station (STA), which is a transceiver (transmitter / receiver) that converts a digital signal distributed between communication devices into a radio signal. The communication device is connected to an access point (AP) that receives and distributes data packets with other devices and / or networks. STAs are either wireless network interface card (NIC) adapters connected to devices known in the art, integrated wireless modules that are part of the device, and external adapters (USB), PCMCIA cards or USB dongles (self-contained ) Can take various forms.

  The present invention provides a new and unique method and apparatus for transmitting information between two nodes, points or terminals in a WLAN as shown in FIG. 1a. Multicast and / or broadcast variable waiting periods and related signal notifications are possible between two or more nodes, points or terminals in the WLAN. FIG. 1b is a flowchart with basic steps 7 and 8 according to some embodiments of the present invention.

  Two nodes, points or terminals in the WLAN operate in a WLAN consistent with FIG. 1 a, the access point (AP) shown in FIG. 2, another appropriate network node or terminal 10, and the STA shown in FIG. Other suitable network nodes or terminals 20 are included. AP 10 and STA 20 comprise corresponding modules 12 and 22, which are configured to allow multicast variable waiting periods and associated signaling between two nodes, points or terminals in WLAN 2 of FIG. 1a. In short, this method enables arbitration of both multicast and broadcast type data.

<Basic implementation>
The basic implementation and cooperation of AP 10 and STA 20 according to some embodiments of the present invention may include the following.

  APs and STAs can demonstrate the ability to accommodate multicast and broadcast variable waiting periods by using new fields in beacons and probe response frames and (re) association request frames. For example, these new fields are described in related US Provisional Patent Application No. 60 / 733,999, filed Nov. 4, 2005. This corresponds to several IEEE 802.11 chapters related to radio resource management capabilities, which are referenced in their entirety. The scope of the present invention is not intended to be limited to using the new fields in the beacon and probe response frames and (re) association request frames described in the above applications. For example, embodiments are envisioned to include using other types of fields in any currently known or future developed beacon and probe response frames and (re) association request frames, and the scope of the present invention is Is intended.

  Multicast and broadcast service can be set using multicast and broadcast service setting signal notification. At this signaling stage, multicast and broadcast service waiting periods are agreed upon. The STA proposes a waiting period according to the multicast and broadcast service characteristics, and the AP can accept the proposal or define a new waiting period. All terminals receiving the same multicast and broadcast signals should use the same waiting period. For example, multicast service configuration is described in the aforementioned related US Provisional Patent Application No. 60 / 733,999 which corresponds to several chapters of IEEE 802.11 related to frame formats. However, the scope of the present invention is not intended to be limited to using the multicast service configuration described therein. Embodiments are envisioned to include, for example, using any other type of multicast service configuration now known or developed in the future, and the scope of the present invention is intended.

  Further, the AP can advertise that the active standby period is each beacon and probe response frame by transmitting the multicast service information / information element. As an example, this information element is described in US Provisional Patent Application No. 60 / 733,999 which corresponds to several chapters of IEEE 802.11. However, embodiments are envisioned to include using any other type of information element now known or later developed, and the scope of the present invention is intended. Also, by using this element, the AP can indicate that there is buffered broadcast data (buffer broadcast data) and / or buffered multicast information belonging to a certain multicast group (buffer information indication). In general, having a multicast service information field in beacons and probe responses is valuable information because a roaming STA can immediately know what the active multicast service in the BSS is.

  The novel features of operation during power saving mode are consistent with and form part of several chapters of IEEE P802.11 and are described as follows.

<Multicast and broadcast enhanced power management>
With multicast and broadcast enhanced power management according to some embodiments of the present invention, variable service periods for multicast and broadcast services can be generated.

  Service periods for multicast and broadcast services are generated using multicast and broadcast service setting signal notifications. A non-AP STA that wants to join a multicast group can propose a multicast waiting period to the AP. Multicast and broadcast waiting periods can be specified in multiples of beacon periods or in units of time units (TUs). The duration of TU is 1024 μs. The AP selects the multicast and broadcast standby period, and indicates the standby period in the multicast and broadcast service setting response frame, the multicast service mode change frame, and the beacon and probe response frame.

<AP operation>
When an enhanced multicast service according to some embodiments of the present invention is used, the AP transmits a beacon with a complete multicast service information field in each beacon.

  In another embodiment of the invention, a complete multicast service information field is transmitted in each DTIM beacon. In the TIM beacon, the AP transmits a multicast service information element including information of a multicast service that transmits data after this TBTT. When multicast data transmission is scheduled after TBTT and the multicast address is not included in the multicast service information, the data of the multicast address is not transmitted after TBTT. The multicast service information element transmitted after the TBTT of the TIM beacon does not include information on the multicast service that transmits data during the TU. When frames belonging to a specific multicast group are buffered, the buffer information indication bit is set.

  When enhanced multicast and broadcast services according to some embodiments of the present invention are used, the AP transmits all multicast frames belonging to a particular multicast group after the service period specified for that multicast and broadcast service. . A continuation data (More Data) field in the MAC header of each multicast frame is set to indicate that there is more buffered multicast MSDU from the multicast address. When the AP is unable to send all buffered multicast MSDUs before the next TBTT, it indicates that the AP will continue to deliver multicast MSDUs by setting the buffer information indication bit in the multicast service information field to 1. The buffer information indication bit is set to 1 until all buffered multicast MSDUs are transmitted.

<Reception Operation of Non-AP STA in Power Saving (PS) Mode>
When enhanced multicast and broadcast services according to some embodiments of the present invention are used, non-AP STAs are activated before a specified multicast and broadcast wait period. A non-AP STA determines whether the continuation data field of the multicast MSDU indicates that there is no longer a buffered multicast MSDU, or the multicast service is no longer included in the multicast service information field, or the buffer information indication field is no longer buffered. It remains active until it shows no MSDU.

  For compatibility with legacy systems, broadcast and multicast information may need to be delivered in the traditional way as well, unless the AP is confident that all relevant STAs can use enhanced broadcast and / or multicast services. . STAs using enhanced broadcast and / or multicast services may need to consider this to avoid duplication of frames.

<Alternative implementation>
Alternative implementation options are:
The AP itself can know the multicast service characteristics, and can set the standby period independently without notifying the multicast service setting signal.
-Multicast service information can also be transmitted in a separate frame. According to this method, the beacon overhead is reduced. Conversely, this may not be good for a roaming STA, for example. Also, in terms of power savings, it is good that this information appears in a known period so that the STA can optimize the standby period.
• Instead of using a full multicast MAC address in the signal notification stage, a compression format can be used.
As described in the present invention, the AP can set a multicast service information element for all beacons.

<Realization of module function>
The functions of the AP 10 and the STA 20 described above can be realized by the corresponding modules 12 and 22 shown in FIGS. By way of example and as described herein, the functionality of modules 12 and 22 can be implemented using hardware, software, firmware, or a combination thereof. However, the scope of the present invention is not limited by these specific examples. In a typical software implementation, modules 12 and 22 consist of a microprocessor, a random access memory (RAM), a read only memory (ROM), an input / output device, a control, data and address bus connecting them, 1 or a plurality of microprocessor-based architectures. Those skilled in the art will be able to program such microprocessor-based implementations to perform the functions described herein without undue experimentation. The scope of the present invention is not intended to be limited to specific implementations using currently known technology or technology that will be developed in the future. Further, the scope of the present invention is intended to include modules 12 and 22 being independent modules as shown, or in combination with another circuit implementing another module.

  The other modules 14 and 24, and their functions, are known in the art and do not themselves form the underlying invention and will not be described in detail here. For example, another module 24 forms part of a conventional mobile phone or terminal, such as a UMTS subscriber identity module (USIM) and mobile device (ME) module, known in the art and not described in detail here. Other modules may be included.

  The present invention allows a variable waiting (sleep) period for multicast services, thereby enabling more optimal power savings for STAs. It also separates broadcast and multicast services with different indications for different waiting periods and buffered data. In addition, multicast transmission information being executed can be given to a STA that is roaming by multicasting multicast service information, and this information can speed up multicast service setting.

<General mobile communication system (UMTS) packet network architecture>
4a and 4b show a general mobile communication system (UMTS) packet network architecture. In FIG. 4a, the UMTS packet network architecture includes main components: user equipment (UE), UMTS terrestrial radio access network (UTRAN), and core network (CN). The UE is connected to the UTRAN via a radio interface (Uu), while the UTRAN is connected to the CN via a (wired) Iu interface. FIG. 4b shows some further architectural details, in particular UTRAN includes multiple radio network subsystems (RNS), each RNS each including at least one radio network controller (RNC). Each RNC can connect to multiple Node Bs that are elements of UMTS corresponding to GSM base stations. Each Node B can wirelessly connect to a plurality of UEs via the radio interface (Uu) shown in FIG. 4a. Even if one or more Node Bs are connected to different RNCs, a specific UE can be wirelessly connected to multiple Node Bs. For example, UE1 in FIG. 4b can wirelessly connect to Node B2 of RNS1 and Node B3 of RNS2, where Node B2 and Node B3 are adjacent Node Bs. Another RNS RNC is connected by an Iur interface. The Iur interface allows a moving UE to stay connected with both RNCs when moving from a cell belonging to Node B of one RNC to a cell belonging to Node B of another RNC. By fusing the IEEE 802.11 WLAN system in FIG. 1a with the (UMTS) packet network architecture in FIGS. 4a and 4b, the STA will take the form of a UE such as a mobile phone or mobile terminal. Collaboration between the WLAN shown in FIG. 1a (IEEE 802.11) and other technologies such as those shown in FIGS. 4a and 4b (eg 3GPP, 3GPP2 or 802.16) is currently being defined in the 3GPP and 3GPP2 protocol specifications. is there. The scope of the present invention is intended to include the same implementations associated with such UMTS packet network architectures.

<Scope of the present invention>
Accordingly, the present invention includes features of components, combinations of elements, and arrangements of parts illustrated in the components described herein.

  Thus, it can be seen that the above objectives and what will become apparent from the above description can be achieved efficiently, and certain modifications can be made in the above constructions without departing from the scope of the present invention. All matters contained in the above description or shown in the accompanying drawings are intended to be illustrative and not limiting.

FIG. 1 illustrates an IEEE 802.11 WLAN system according to some embodiments of the present invention. 2 is a flowchart with the basic steps of a method according to some embodiments of the invention. FIG. 6 illustrates an access point (AP) according to some embodiments of the present invention. FIG. 2 illustrates a wireless station (STA) according to some embodiments of the present invention. FIG. 2 illustrates a general mobile communication system (UMTS) packet network architecture according to some embodiments of the present invention. FIG. 2 illustrates a general mobile communication system (UMTS) packet network architecture according to some embodiments of the present invention.

Claims (37)

A signal containing information on a first proposed multicast waiting interval for a first multicast group from a second node, point or terminal in the wireless local area network at a first node, point or terminal in the wireless local area network Receiving the step,
Determining a first multicast waiting interval for the first multicast group based at least in part on the information contained in the signal at the first node, point or terminal;
Determining a second multicast waiting interval for a second multicast group at the first node, point or terminal;
It has a multicast wait interval of the first for the multicast group of the first is different from the second multicast wait interval for the second multicast group, methods. The first node, point or terminal and the second node, point or terminal are an access point in the wireless local area network, another appropriate network node or terminal, a radio station, or another appropriate network. The method according to claim 1, comprising: a node or a terminal. The access point and the radio station uses the new field of the beacon and the probe response frame and (re) association request frame may indicate an ability to support multicast wait interval A method according to claim 2 . A multicast service setting signaling, further comprising the step of setting a multicast service method of claim 1. In this signaling phase may be a multicast wait interval is agreed between the first node in the wireless local area network, a point or terminal, said second node, a point or terminal according to claim The method according to 1. Signal from the radio station may include information about multicast wait interval proposal based on the multicast service characteristic, the access point may accept the multicast wait interval draft or to define a new multicast wait interval, The method of claim 2. The access point also, by sending the multicast service information and information elements in the beacon and probe response frames, it is possible to advertise the active multicast wait interval The method of claim 6. The access point also may indicate whether there is a multicast information buffered belonging to the broadcast data, and / or multicast groups the buffered method of claim 7. A signal containing information about the first proposed multicast waiting interval for the first multicast group from the first node, point or terminal in the wireless local area network to the second node, point or terminal in the wireless local area network A step of sending
Receiving a first multicast waiting interval for the first multicast group at the first node, point or terminal;
And the first multicast waiting interval for the first multicast group is different from a second multicast waiting interval for a second multicast group related to the second node, point or terminal. . The first node, point or terminal and the second node, point or terminal are an access point in the wireless local area network, another appropriate network node or terminal, a radio station, or another appropriate network. The method according to claim 9, comprising: a node or a terminal. The access point and the radio station uses the new field of the beacon and the probe response frame and (re) association request frame may indicate an ability to support multicast wait interval The method of claim 10 . A multicast service setting signaling, further comprising the step of setting a multicast service method of claim 9. In this signaling phase, the multicast waiting interval can be agreed between the first node in the wireless local area network, a point or terminal, said second node, a point or terminal the method of claim 9. Signal from the radio station may include information about multicast wait interval proposal based on the multicast service characteristic, the access point may accept the multicast wait interval draft or to define a new multicast wait interval, The method of claim 10. The access point also, by sending the multicast service information and information elements in the beacon and probe response frames, it is possible to advertise the active multicast wait interval The method of claim 14. The access point also may indicate whether there is a multicast information buffered belonging to the broadcast data, and / or multicast groups the buffered method of claim 15. A first node, point or terminal,
From a second node, point or terminal in the wireless local area network, receiving a signal including information on the first multicast waiting interval proposal for the first multicast group, and based on the information included in the signal, the determining a first multicast wait interval for the first multicast group, further comprising one or more modules configured to determine a second multicast wait interval for the second multicast group,
Multicast wait interval of the first for the multicast group of the first is different from the second multicast wait interval for the second multicast group,
First node, point or terminal. The first node, point or terminal and the second node, point or terminal are an access point in the wireless local area network, another appropriate network node or terminal, a radio station, or another appropriate network. comprising a node or terminal, a first node according to claim 17, point or terminal. The access point and the radio station uses the new field of the beacon and the probe response frame and (re) association request frame may indicate an ability to support multicast wait interval, according to claim 18 second A node, point or terminal. The one or more modules, the multicast service setting signaling is configured to set the multicast service, the first node according to claim 17, point or terminal. In this signaling phase may be a multicast wait interval is agreed between the first node in the wireless local area network, a point or terminal, said second node, a point or terminal according to claim The first node, point or terminal according to 17. Signal from the radio station may include information about multicast wait interval proposal based on the multicast service characteristic, the access point may accept the multicast wait interval draft or to define a new multicast wait interval, The first node, point or terminal according to claim 18. The access point also, by sending the multicast service information and information elements in the beacon and probe response frames, it is possible to advertise the active multicast wait interval, the first node according to claim 22, point or terminal . The access point also may indicate whether there is a multicast information buffered belonging to the broadcast data, and / or multicast groups the buffered first node according to claim 23, point or terminal . The multicast or broadcast information and transmits the first node, point or terminal using a "continuous data" bit indicating that the buffered data from the same multicast or broadcast address, claim 17 A first node, point or terminal as described in. A computer program stored on a machine readable medium when executed on a module of a first node, point or terminal, such as an access point in a wireless local area network,
Receiving, at the first node, point or terminal, a signal including information on a first multicast waiting interval proposal for a first multicast group from a second node, point or terminal in the wireless local area network; When,
Determining a first multicast waiting interval for the first multicast group based at least in part on the information contained in the signal at the first node, point or terminal;
Determining a second multicast waiting interval for a second multicast group at the first node, point or terminal;
A computer program for executing a method comprising:
Multicast wait interval of the first for the multicast group of the first is different from the second multicast wait interval for the second multicast group, computer program. It said first node, point or processor in the terminal, the controller or by a computer program executed by other appropriate module, further comprising the step of implementing the method steps The method of claim 1. Sending multicast or broadcast information using a “continuation data” bit that indicates that the first node, point, or terminal is buffering data from the same multicast or broadcast address ; The method of claim 1. A device,
A signal containing information about the first proposed multicast waiting interval for the first multicast group from the first node, point or terminal in the wireless local area network to the second node, point or terminal in the wireless local area network One or more modules configured to receive a first multicast waiting interval for the first multicast group at the first node, point or terminal in the wireless local area network,
The apparatus, wherein the first multicast waiting interval for the first multicast group is different from a second multicast waiting interval for a second multicast group associated with the second node, point or terminal . The device and the second device, the access point in the wireless local area network, including addition of a suitable network node or terminal, a radio station, in addition to the appropriate network node or terminal and, according to claim 29 apparatus. In this signaling phase, the multicast wait interval, and the device in the wireless local area network, may be agreed upon between the second apparatus, Apparatus according to claim 29. The access point and the radio station uses the new field of the beacon and the probe response frame and (re) association request frame may indicate an ability to support multicast wait interval Apparatus according to claim 30 . The one or more modules, the multicast service setting signaling further configured to set the multicast service device of claim 29. Signal from the radio station may include information about multicast wait interval proposal based on the multicast service characteristic, the access point may accept the multicast wait interval draft or to define a new multicast wait interval, The apparatus of claim 30. Using said multicast wait interval at least partially, said second node, further comprising the step of providing a communication signal to the point or terminal, method of claim 1. The one or more modules, using said multicast wait interval at least partially, said second node configured to provide the communication signal to the point or terminal, first of claim 17 Node, point or terminal. The access point also, by sending the multicast service information and information elements in the beacon and probe response frames, it is possible to advertise the active multicast wait interval Apparatus according to claim 34.

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