TWI383696B - Method and systems for variable rate broadcast with soft handoff - Google Patents

Description

Method and system for variable rate broadcast with soft handover

This disclosure is a large system regarding wireless communications. More specifically, embodiments disclosed herein relate to providing variable rate broadcast with soft handoff in wireless communications.

Wireless communication systems are widely deployed to provide various types of communications, such as voice and data, to multiple users. Such systems may be based on coded multidirectional proximity (CDMA), timed multidirectional proximity (TDMA), frequency division multidirectional proximity (FDMA) or other multidirectional proximity techniques. A wireless communication system can be designed to construct one or more standards such as IS-95, cdma2000, IS-856, W-CDMA, TD-SCDMA, and other standards.

Broadcast services and multicast services have been proposed to efficiently transfer large amounts of data from a single source point to a group of users in a wireless communication system. Content for such point-to-multipoint services includes news, stock quotes, sports events, movies, audio and video clips, and other multimedia materials. As the demand for multimedia data transmission grows, there is a challenge to increase spectral efficiency and maximize the data rate of broadcast/multicast services.

Embodiments disclosed herein relate to methods and systems for providing a variable rate broadcast service with soft handoff in a communication system.

The unicast communication described herein may generally refer to any one-to-one audio and/or data transmission from a single source to a single receiver. In a wireless (e.g., cellular) communication system, a unicast communication may involve transmission from one or more transmitters (e.g., at an access network) to a single receiver (e.g., an access terminal). . A broadcast/multicast communication (or service) as described herein may generally refer to any point-to-multipoint data transmission from a single source to a group of users in a broadcast area, which may include one or more Sections (or units).

For a particular broadcast service, an access network can receive a stream of information from a content server and transmit the information to a group of users in a broadcast area on a designated channel. The content of a broadcast communication (referred to herein as "broadcast content") may be sealed in a data packet (referred to herein as a "broadcast packet") as specified by a suitable agreement, such as the Internet Protocol (IP). A broadcast content may include, but is not limited to, this document, audio, pictures, video, data files, software upgrades, and other information.

A broadcast/multicast service may have a controlled access, such as a user who only subscribes to the service receives the desired broadcast content on its access terminal. Unsubscribed users cannot access the broadcast/multicast service. For example, such controlled access can be achieved by encrypting the broadcast transmission/content in a manner that only allows the subscriber to decrypt the received broadcast content.

An access network controller (ANC) may refer to a portion of a communication system configured to establish an interface with a core network (eg, a packet data network) and to deliver an access terminal (AT) to the core network Data packets between the roads, performing various radio access and link maintenance functions (such as soft handover), controlling radio transmitters and receivers, and the like. An ANC may include and/or construct a base station controller (BSC) function, such as functionality found in a second or third generation wireless network. An ANC and one or more access points (APs) may form part of an access network (AN). One of the APs described herein may also be referred to as a Base Station Transceiver System (BTS), an Access Network Transceiver (ANT), a Data Station Hub Transceiver (MPT), or a Node B (eg, in a W - in the CDMA type system) and so on. A unit can refer to a coverage area served by an AP. A unit may further include one or more sections. A broadcast area can include one or more units.

One of the ATs described herein can refer to various types of devices including, but not limited to, a wireless telephone, a cellular telephone, a laptop, a wireless communication personal computer (PC) card, and a number of personal assistants (PDAs). , an external or internal data machine, and so on. An AT can be any data device that communicates via a wireless channel or via a wired channel, such as via an optical fiber or coaxial cable. An AT can have various names such as access unit, subscriber unit, mobile station, mobile device, mobile unit, mobile phone, mobile, remote station, remote terminal, remote unit, user equipment, user equipment , handheld devices, and more. Different ATs can be incorporated into one system. The AT can be mobile or fixed and can be distributed throughout a communication system. At a particular time, an AT can communicate with one or more APs on a forward link and/or a reverse link. The forward link (or downlink) refers to the transmission from an AP to an AT. The reverse link (or uplink) refers to the transmission from the AT to the AP.

In a wireless communication system that constructs a broadcast/multicast service, soft handover is used to increase the broadcast transmission rate. In soft handoff, the same transmission from one or more APs can be received and combined at one AT, thus allowing the AT to support a higher data rate. Since a broadcast content is intended to be received by a plurality of users dispersed in a broadcast area, the broadcast transmission is generally the same in various units in the broadcast area. In some systems, the broadcast transmission can be in the CDMA format, and each subscription AT can softly combine transmissions from APs serving different units, for example, using a Rake receiver and/or an equalization receiver. In other systems, the broadcast transmission may have an orthogonal frequency division multiplexing (OFDM) format, and each subscription AT may, for example, use a Fast Fourier Transform (FFT) based demodulation variant and softly combine the services from the service. Transmission of APs in different units.

In reality, however, cells in a propagation region have different supportable data rates. For example, consider a broadcast area that includes a dense urban network having a generally small size limited capacity unit that routes a suburban network with a larger coverage area. Surrounded. Since the supported data rate typically varies with the total received power (eg, from all units involved in soft handover) to the total interference power, the maximum supported broadcast rate for a small city unit may be larger than that of a large suburb. The unit can support a high broadcast rate. However, in order to construct soft handoffs in such systems, it may be necessary to broadcast transmissions at the lowest supported rate among the various units of the broadcast area, thus overly limiting the spectral efficiency of the system.

There is therefore a need to improve spectral efficiency and maximize the broadcast transmission rate of broadcast/multicast services.

In order to improve overall spectral efficiency, it is desirable to operate the broadcast transmission at a variable rate associated with the coverage of the unit. In order to maximize the broadcast transmission rate, it is necessary to operate the broadcast transmission in soft handover. Embodiments disclosed herein relate to methods and systems for providing broadcast/multicast services at a variable rate while maintaining soft handoff, thereby increasing overall spectral efficiency and maximizing broadcast transmission rates.

In one embodiment, a plurality of APs (e.g., serving various units in a broadcast area) may transmit a broadcast content based on a rate setting. The rate setting includes a plurality of distinct data rates, each rate being associated with a transport format (e.g., the number of transmission slots designated for transmitting a data packet) configured to allow incrementally combining the broadcast packets transmitted by the AP (eg based on the basis of each slot at a subscription AT). By way of example, consider a rate setting that includes three data rates associated with, for example, 1-slot, 2-slot, and 3-slot transmission formats: R ₁ =R (eg, 1843.2 kbps), R ₂ =R/2 (eg, 921.6) Kbps) and R ₃ = R/3 (eg 614.4 kbps). The first slots of the broadcast transmission at three rates are the same and may be soft combined. The second slots of the broadcast transmission at rates R ₂ and R ₃ are identical and may also be soft combined. Thus, as described above, in order to construct a variable rate broadcast, the rate setting must be configured to allow for incremental combinations. As described further below, the rate setting can also be configured to support soft handoff in the broadcast area.

Various aspects, features, and embodiments are described in further detail below.

1 illustrates a schematic diagram of a communication system 100 in which various disclosed embodiments can be constructed. By way of example, system 100 can include a plurality of APs 110, such as APs 110a through 110c, each serving a unit (not explicitly shown in FIG. 1). Various ATs 120 including ATs 120a through 120d are dispersed throughout various units of the system. Each AT 120 can communicate with one or more APs 110 depending on, for example, whether the AT is valid and whether it is in soft handover.

In system 100, an ANC 130 may be in communication with AP 110 and used to provide coordination and control for AP 110. For example, ANC 130 can be configured to control the delivery of audio/data packets via respective APs 110 to ATs 120. The ANC 130 can further communicate with a data network via, for example, a Packet Data Service Node (PDSN) (both not explicitly shown in Figure 1). In some embodiments, system 100 can be configured to support one or more wireless communication standards, such as IS-95, cdma2000, IS-856, W-CDMA, TD-SCDMA, other wireless communication standards, or a combination thereof .

System 100 can also be configured to construct a broadcast/multicast service, for example, in a broadcast area 140. For example, the ANC 130 can deliver a broadcast content (eg, received from a data network that can also include a content server) to the AP 110, and the AP 110 can transmit the broadcast content to the AT in the broadcast area 140. 120.

In an embodiment, the broadcast/multicast service may be performed at a variable rate of soft handover. For example, ANC 130 may select a rate setting that includes a plurality of distinct data rates, each rate being associated with a transmission format configured to allow for incrementally combining broadcast transmissions (as described above). As described further below, the rate setting can be selected with respect to the supportable data rates of the units served by the AP 110 in the broadcast area 140, as well as the requirements to support soft handoffs in such units. The rate setting is also selected based in part on the size of the broadcast content to be transmitted. The ANC 130 can then instruct the AP 110 to transmit broadcast content in accordance with the selected rate setting. The ATs 120 in the broadcast area 140 can incrementally combine (e.g., based on a per slot basis) broadcast packets received from various APs 110. For example, AT 120b may incrementally combine broadcast packets from APs 110a, 110b received via, for example, forward links 150, 152, respectively. The AT 120c may incrementally combine the broadcast packets from the APs 110b, 110c received via, for example, the forward links 154, 156, respectively.

As described above, in order to construct a variable rate broadcast with soft handoff, the broadcast data rate and the corresponding transport format for a particular unit need to be configured to support the unit and the neighboring units that support the unit for soft handover support soft Handover (as explained in the example below). For purposes of illustration and clarity, in the following examples, a soft handover coverage of a particular unit (eg, one or more adjacent units supporting the unit in a soft handover) extends to an adjacent unit. This should not be construed as limiting. The underlying principles and procedures so described can be applied to other cases where the soft handover coverage extends beyond adjacent cells.

2A through 2D illustrate an embodiment of a broadcast area 200 including a plurality of units in a communication system. For the sake of clarity and clarity, the elements in these figures are shown as having a uniform shape and size. This should not be construed as limiting. In other embodiments, the units can have different sizes and shapes (and are omnidirectional or divided). Also for the sake of clarity and simplicity, the APs serving these units and the ATs dispersed in such units are not explicitly shown in these figures.

Consider the A unit 210 illustrated in Figure 2A. A unit 210 can be, for example, part of a dense urban network capable of supporting a higher data rate. It is assumed that the A unit 210 can support a data rate R corresponding to an n-slot (n is an integer, eg, n=1) transmission format. In order to support soft handoff in A-cell 210, neighboring cells, such as those illustrated in a similar pattern, are also required to be capable of supporting a 1-slot transmission format.

FIG. 2B illustrates a set of B units 220. It is assumed that each B unit 220 is also capable of supporting the data rate R, and thus supports a 1-slot transmission format. In order to support soft handoff in each B-unit 220, adjacent cells, such as those illustrated in a similar pattern, are also required to be capable of supporting a 1-slot transmission format.

2C illustrates a set of C units 230, which may be, for example, part of a larger suburban network. It is assumed that each C unit 230 can support a data rate (n/m) R corresponding to the 3-slot transmission format (n and m are integers, for example, n=1, m=3). In order to support soft handoff in each C-unit 230, neighboring cells, such as those illustrated in a similar pattern, are also required to be capable of supporting a 3-slot transmission format.

In order to satisfy the requirements of soft handover in all units (for example, A unit 210, B unit 220, and C unit 230) as described above, each B unit 220 needs to be able to support a 1-slot transmission format and a 3-slot transmission format to A unit 210 and C unit 230 are assisted in soft handover. 2D (which is illustrated in a pattern description B unit 220 similar to the pattern used for C unit 230), because the data rate is the first of the broadcast transmissions in both the 1-slot transmission format and the 3-slot transmission format. The slots are the same, so each B-unit 220 is assigned a 3-slot transmission format. In this manner, the first slots of the broadcast transmission in unit A 210 are the same and can be soft combined. Because the B unit 220 can support the 1-slot transmission format, the AT in the B unit can successfully decode the broadcast packet after the first slot; the remaining two slots of the broadcast transmission can be used to support the soft handover in the C unit 230, as shown in the following figure. Further explanation in 3.

Figure 3 illustrates an embodiment of a timeline for broadcast transmission in the embodiment of Figure 2D described above. The legend 310 is used to indicate pairs of indicators for marking each transmission slot. As illustrated in Figure 3, for the A unit, the transmission slot behind the first slot is used for unicast transmission. Because the B unit can support the 1-slot transmission format, the AT in the B unit can successfully decode the broadcast packet after the first slot (same as in the A unit); the remaining two slots are used to support the incremental combination in the C unit (eg, based on each One slot basis).

As illustrated in Figures 2D and 3, the B unit can be used as a "buffer" unit to effectively separate two coverage areas (e.g., A and C units) that support different data rates while maintaining soft handoff. As explained above, such buffer units may be capable of supporting some data rates of neighboring cells (having a higher supported data rate), but are assigned the same as other neighboring cells (having a lower supported data rate) The transport format, thus allowing neighboring units to receive broadcast transmissions of different data rates while maintaining soft handoff (e.g., by allowing incremental combinations as described above). This variable rate approach improves overall spectral efficiency by minimizing the portion of the slot configured for broadcast transmission while maximizing the broadcast data rate by maintaining soft handover. As shown in FIG. 3, if there is no such method, the broadcast transmission to the A unit must be a 3-slot transmission format, and as a result, the transmission slot configured for unicast transmission must also be used for broadcast transmission, thus limiting the overall spectrum. effectiveness.

4 illustrates a flow diagram of a process 400 that can be used in an embodiment to construct a variable rate broadcast with soft handoff. Step 410 assigns a nominal rate to the unit with respect to a unit being softly handed over with one or more neighboring units (e.g., in a particular soft handover coverage). The nominal rate may consider, for example, soft handoff support that the neighboring unit will provide. In some embodiments, such as described above, the nominal data rate assigned to various units in a broadcast area can be configured to allow for incremental combinations. Step 420 identifies a minimum (or lowest) nominal rate of a neighboring unit (e.g., the same neighboring unit considered in step 410) assigned to each unit and in the soft handoff of the unit. Step 430 assigns a broadcast data rate equal to the minimum nominal rate thus identified to each unit.

FIG. 5 illustrates a flow diagram of a process 500 that can be used in an embodiment to construct a variable rate broadcast with soft handoff. Step 510 selects a rate setting that includes a plurality of distinct rates, each rate being associated with a transmission format. Step 520 instructs a plurality of APs to transmit a broadcast content configured to allow for incrementally combining the broadcast packets transmitted by the AP (e.g., based on each slot basis at an AT). In some embodiments, such as the above description, the data rate in the rate setting and the corresponding transmission format may be selected with respect to the supportable data rate of the unit served by the AP, and the restrictions imposed by the neighboring unit to support soft handover, and Assign it to the AP. The rate setting can also be selected based in part on the size of the broadcast content to be transmitted.

6 depicts a flow diagram of a process 600 that can be used in an embodiment to construct a variable rate broadcast with soft handoff. Step 610 assigns n slot assignments to a first AP for transmitting a broadcast content, and assigns (m-n) slots for unicast (m and n are integers and m > n). Step 620 assigns m slots to a second AP for transmission of broadcast content. Step 630 assigns m slots to a third AP for transmission of broadcast content. In an embodiment, the first AP may provide service to a first unit capable of supporting a data rate R. The second AP provides service to a second unit adjacent to the first unit, and the second unit is also capable of supporting the data rate R. The third AP provides service to a third unit adjacent to the second unit, the third unit being capable of supporting a data rate (n/m) R such as described above.

FIG. 7 depicts a flow diagram of a process 700 that can be used in an embodiment to construct a variable rate broadcast with soft handoff. Step 710 sets a slot indicator i to zero. Step 720 selects a transmission slot and increments the slot indicator by one (i = i + 1). Step 730 determines if i m, where m is the number of transmission slots configured for broadcast transmission. If the result of step 730 is "YES", then step 740 follows and identifies the broadcast packet received from the plurality of APs in slot i. Step 750 then soft combines the broadcast packets received in slot i. (Note that for broadcast transmission in CDMA format, the received signal may first be despread before being soft-combined. For broadcast transmission in OFDM format, the received signal can be directly soft combined.) Process 700 then returns to step 720 and continues to the next transfer slot. If the result of step 730 is "NO", then as shown in step 760, process 700 can, for example, continue processing the unicast transmission.

8 shows a block diagram of a device 800 that can be used to construct certain disclosed (such as described above) embodiments. By way of example, apparatus 800 can include a rate setting selection unit (or module) 810 configured to select a rate setting including a plurality of distinct data rates, each rate associated with a transmission format; and an instruction Unit 820 is configured to instruct a plurality of APs to transmit broadcast content in accordance with the rate setting. The rate setting can be configured to allow incrementally combining the broadcast packets transmitted by the AP (as described above).

In some embodiments, rate setting selection unit 810 can, for example, be configured to perform the process 400 illustrated in FIG. The instruction unit 820 can, for example, be configured to perform the process 600 illustrated in FIG.

In the device 800, the rate setting selection unit 810 and the instruction unit 820 can be coupled to a communication bus 830. A processing unit 840 and a memory unit 850 can also be coupled to the communication bus 830. Processing unit 840 can be configured to control and/or coordinate the operation of various units. Memory unit 850 can include instructions that processor 840 will execute.

In some embodiments, device 800 can be constructed in an ANC (such as ANC 130 illustrated in Figure 1), a central controller for a network, or other network infrastructure components.

9 shows a block diagram of a device 900 that can be used to construct certain disclosed (such as described above) embodiments. By way of example, apparatus 900 includes a receiving unit (or module) 910 configured to receive data packets transmitted from a plurality of APs; an identification unit 920 configured to identify broadcast packets in the received data packets And an incremental combining unit 930 configured to incrementally combine the identified broadcast packets (eg, based on a per slot basis). In some embodiments, receiving unit 910, identifying unit 920, and incremental combining unit 930 can, for example, be configured to perform the process 700 illustrated in FIG.

In the device 900, the receiving unit 910, the identifying unit 920, and the incremental combining unit 930 can be coupled to a communication bus 940. A processing unit 950 and a memory unit 960 can also be coupled to the communication bus 940. Processing unit 950 can be configured to control and/or coordinate the operation of various units. Memory unit 960 can include instructions that processing unit 950 will execute.

In some embodiments, device 900 can be constructed in an AT or other data receiving component.

Embodiments disclosed herein (such as described above) provide some embodiments of a variable rate broadcast service with soft handoff. There are other embodiments and constructions.

The various units/modules and other embodiments of Figures 8-9 can be constructed in hardware, software, firmware, or a combination thereof. In a hardware architecture, various units can be constructed in one or more special application integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), and field programmable gate arrays (FPGAs). , a processor, a microprocessor, a controller, a microcontroller, a programmable logic device (PLD), other electronic units, or any combination thereof. In a software construction, various units may be constructed using modules (eg, programs, functions, etc.) that perform the functions described herein. The software code can be stored in a memory unit and executed by a processor (or a processing unit). The memory unit can be constructed within the processor or external to the processor, and the memory unit can be communicatively coupled to the processor via various components known in the art.

Various disclosed embodiments can be constructed in a controller, an AT, and other components for providing broadcast/multicast services. The embodiments disclosed herein are applicable to a data processing system, a wireless communication system, a one-way broadcast system, and any other system that requires efficient transmission of information.

Those skilled in the art should be aware that any of a variety of different processes and techniques can be used to represent information and signals. For example, data, instructions, commands, information, signals, bits, symbols, which may be referred to throughout the above description, may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, light fields and particles, or any combination thereof. And wafers.

Those skilled in the art should further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein can be constructed as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of functionality. The functionality is built as a hardware or software depending on the particular application and design constraints imposed on the overall system. The skilled artisan can construct the described functions for each particular application in various ways, but these construction decisions should not be construed as causing a departure from the scope of the invention.

A general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic can be used. The various hardware blocks, modules, and circuits described in conjunction with the embodiments disclosed herein are implemented or executed in any combination of discrete hardware components or any combination of the functions described herein. A general purpose processor can be a microprocessor, or the processor can be any conventional processor, controller, microcontroller, or state machine. A processor can also be constructed as a combination of computing devices, such as a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or a combination of any other such configuration.

The steps of a method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly in a hardware, in a software module executed by a processor, or in a combination of the two. A software module can reside in random access memory (RAM), flash memory, read only memory (ROM), electrically programmable read only memory (EPROM), and electrically erasable programmable read only memory ( EEPROM), scratchpad, hard drive, a removable disc, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor, such that the processor can read information from the storage medium and write the information to the storage medium. Alternatively, the storage medium can be part of a processor. The processor and the storage medium can reside in an ASIC. The ASIC resides in an AT. Alternatively, the processor and the storage medium may reside as an discrete component in an AT.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. The various modifications of the embodiments are obvious to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not intended to be limited to the embodiments shown herein, but rather the broadest scope of the principles and novel features disclosed herein.

100. . . Communication Systems

110a-110c. . . Access point

120a-120d. . . Access terminal

130. . . Access network controller

140. . . Broadcast area

150. . . Forward link

152. . . Forward link

154. . . Forward link

156. . . Forward link

200. . . Broadcast area

210. . . Unit A

220. . . Unit B

230. . . Unit C

300. . . Broadcast transmission timeline

310. . . legend

400. . . deal with

500. . . deal with

600. . . deal with

700. . . deal with

800. . . Device

810. . . Rate setting selection unit/rate setting selection module

820. . . Command unit

830. . . Communication bus

840. . . Processing unit/processor

850. . . Memory unit

900. . . Device

910. . . Receiving unit/receiving module

920. . . Identification unit

930. . . Incremental combination unit

940. . . Communication bus

950. . . Processing unit

960. . . Memory unit

1 illustrates an embodiment of a communication system; FIGS. 2A through 2D illustrate an embodiment of constructing a variable rate broadcast with soft handover in a broadcast area of one of the communication systems; and FIG. 3 illustrates a broadcast in the embodiment of FIG. 2D An embodiment of a timeline of transmission; Figure 4 illustrates a flow diagram of a process that can be used in an embodiment to construct a variable rate broadcast with soft handoff; Figure 5 illustrates a flow diagram of a process that is available In one embodiment, a variable rate broadcast with soft handoff is constructed; FIG. 6 illustrates a flow diagram of a process that can be used in an embodiment to construct a variable rate broadcast with soft handoff; FIG. Processing a flow chart that can be used in an embodiment to construct a variable rate broadcast with soft handoff; Figure 8 shows a block diagram of a device in which certain disclosed embodiments can be constructed; 9 shows a block diagram of a device in which certain disclosed embodiments may be constructed.

300. . . Broadcast transmission timeline

310. . . legend

Claims (24)

An apparatus for wireless communication, comprising a processor configured to: select a rate setting comprising a plurality of distinct data rates, each rate associated with a transmission format; and indicating a plurality of accesses A point transmits a broadcast content according to the rate setting, the rate setting being configured to allow incrementally combining the broadcast packets transmitted by the access points based on the plurality of distinct data rates and the transport formats. The device of claim 1, wherein the processor is further configured to select the rate setting for a supportable rate of units served by the access points and a request to support soft handover in the units. The device of claim 1, wherein the processor is further configured to select the rate setting based in part on a size of the broadcast content. The device of claim 1, wherein each of the broadcast packets is transmitted in at least one transmission slot, and the broadcast packets are incrementally combined based on a per slot basis. The apparatus of claim 1, wherein the broadcast content is transmitted in one of a coded multi-directional proximity (CDMA) format and an orthogonal frequency division multiplexing (OFDM) format. The device of claim 1, wherein the data setting includes a first data rate R ₁ =R and a second data rate R ₂ =R/2, respectively, associated with the 1-slot, 2-slot, and 3-slot transmission formats, and A third data rate R ₃ = R/3 is used to support incremental combinations based on each slot. A device suitable for wireless communication, comprising: a rate setting selection unit configured to select a rate setting comprising a plurality of distinct data rates, each rate being associated with a transmission format; and an instruction unit configured to indicate a plurality of locations The fetch point transmits a broadcast content according to the rate setting, the rate setting being configured to allow incrementally combining the broadcast packets transmitted by the access points according to the plurality of distinct data rates and the transport formats. The apparatus of claim 7, further comprising a processing unit in communication with the rate setting selection unit and the instruction unit. An apparatus suitable for wireless communication, comprising a processor configured to: assign n slots to a first access point for transmitting a broadcast content, and assign (mn) slots for Unicast transmission (m>n); assigning m slots to a second access point for transmitting the broadcast content; and assigning m slots to a third access point for transmitting the broadcast content. The device of claim 9, wherein the first access point, the second access point, and the third access point are configured to be a first unit, a second unit adjacent to the first unit, and A third unit adjacent to the second unit provides service, and wherein the first unit is capable of supporting a data rate R, and the third unit is capable of supporting a data rate (n/m) R. An apparatus suitable for wireless communication, comprising a processor configured to: assign a nominal rate to each unit with respect to each unit and at least one neighboring unit for soft handover; Identifying a minimum nominal rate assigned to each unit and the at least one neighboring unit; and assigning a broadcast data rate to each unit, the rate being equal to the identified minimum nominal rate. An apparatus for wireless communication, comprising a processor configured to: receive a broadcast packet transmitted from a plurality of access points according to a plurality of distinct data rates, each rate being associated with a transport format And incrementally combining the received broadcast packets. The device of claim 12, wherein each of the broadcast packets is transmitted in at least one of the transport slots, and the broadcast packets are incrementally combined based on a per slot basis. An apparatus for wireless communication, comprising: a receiving unit configured to receive data packets transmitted from a plurality of access points according to a plurality of distinct data rates, each rate being associated with a transport format; An identification unit configured to identify the broadcast packets in the received data packets; and an incremental combination unit configured to incrementally combine the broadcast packets. The device of claim 14, wherein each of the broadcast packets is transmitted in at least one of the transport slots, and the broadcast packets are incrementally combined based on a per slot basis. The device of claim 14, further comprising a processing unit The receiving unit, the identifying unit, and the incremental combining unit communicate. A method for wireless communication, comprising: selecting a rate setting, comprising a plurality of distinct data rates, each rate being associated with a transmission format; and instructing a plurality of access points to transmit a broadcast content according to the rate setting, The rate setting is configured to allow incrementally combining the broadcast packets transmitted by the access points based on the plurality of distinct data rates and the transport formats. The method of claim 17, further comprising selecting the rate setting for a supportable rate of units served by the access points and a requirement to support soft handover in the units. The method of claim 17, further comprising selecting the rate setting based in part on a size of the broadcast content. A method for wireless communication, comprising: assigning n slots to a first access point for transmitting a broadcast content, and assigning (mn) slots for unicast transmission (m>n); Assigning m slots to a second access point for transmitting the broadcast content; and assigning m slots to a third access point for transmitting the broadcast content. The method of claim 20, wherein the first access point, the second access point, and the third access point are respectively configured as a first unit, a second unit adjacent to the first unit, and adjacent to the first unit A third unit of the second unit provides service, and wherein the first unit is capable of supporting a data rate R, and the third unit is capable of supporting a data rate (n/m) R. A method for wireless communication, comprising: Receiving broadcast packets from a plurality of access points; and incrementally combining the received broadcast packets. The method of claim 22, wherein each of the broadcast packets is transmitted in at least one transmission slot, and the method further comprises incrementally combining the broadcast packets based on a per slot basis. A method for wireless communication, comprising: assigning a nominal rate to each unit with respect to each unit and at least one neighboring unit; the identification is assigned to each unit and the at least one neighboring unit a minimum nominal rate; and assigning a broadcast data rate to each unit at a rate equal to the identified minimum nominal rate.