HK1063251B - Method and apparatus for providing multiple quality of service levels in a wireless packet data services connection - Google Patents

Description

Method and apparatus for providing multiple quality of service classes in a wireless packet data service connection

Background

FIELD

The present invention relates to wireless communications. More particularly, the present invention relates to an innovative method and apparatus for providing multiple quality of service levels between a mobile station and a wireless network in a wireless packet network.

Background

The use of Code Division Multiple Access (CDMA) modulation techniques is one of several techniques for facilitating communication in a system having a large number of system users. Other multiple access communication system techniques, such as Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA) and AM modulation schemes such as single sideband Amplitude Companding (ACSSB), are well known in the art. These technologies have been standardized to facilitate interoperability between products produced by different companies. Code division multiple access communication SYSTEMS have been standardized in the united states by the wireless communication industry alliance TIA/EIA/IS-95-B entitled mobile STATION-BASE STATION COMPATIBILITY STANDARD FOR DUAL-MODE WIDEBAND spread spectrum CELLULAR SYSTEMS, herein referred to as IS-95. In addition, a new Standard for CDMA communication Systems has been proposed by the TIA for wireless telecommunications in the united states, entitled "Upper Layer (Layer 3) Signaling Standard for CDMA2000 Spread Spectrum Systems," Release a-addendam 1 "(Upper Layer (Layer 3) signal Standard for CDMA2000 Spread Spectrum Systems, Release a-annex 1), published in year 2000 at 10/27, and referred to herein as" CDMA2000 ".

The international radio consortium has recently required the submission of proposed methods for providing high-rate data and high-quality voice services over wireless communication channels. The first recommendation was published by The Wireless communication industry alliance entitled "The IS-2000 ITU-RRTT conference sub" (IS-2000 ITU-R RTT Candidate submissions). A second proposal was published by The European radio communication industry alliance (ETSI) entitled "The ETSI UMTS Terrestrial Radio Access (UTRA) ITU-R RTT cancer subscription" (ETSI UMTS Terrestrial Radio Access (UTRA) ITU-R RTT Candidate Submission), also referred to as "wideband CDMA" and referred to hereinafter as "W-CDMA". The third proposal was submitted by U.S. tg 8/1 entitled "The UWC-136 Candidate Submission" (UWC-136 Candidate submitter), hereinafter referred to as "EDGE". The contents of these submissions are all open and well known in the art.

IS-95 was originally used to optimize the transmission of variable rate speech frames. Later standards were built upon to support additional non-voice services including packet data services. One such packet Data Service IS standardized in the United states by the Wireless communication industry alliance TIA/EIA/IS-707-A, entitled "Data services Options for spread Spectrum Systems" (Data services Options for spread Spectrum Systems), which IS hereby incorporated by reference and IS hereinafter referred to as "IS-707".

IS-707 describes techniques to provide support for sending Internet Protocol (IP) packet data over IS-95 wireless networks. Packet data is encapsulated into a featureless byte stream using a protocol called the point-to-point protocol (PPP). Using PPP, IP packet data can be transmitted in fragments of any size over a wireless network. The wireless network maintains PPP state information during the PPP protocol session or during periods when a continuous byte stream may be sent as long overhead bytes between PPP end points.

Such a byte stream IS further encapsulated into a series of IS-95 frames using a protocol called the Radio Link Protocol (RLP). RLP includes an error control protocol, and the receiver prompts the transmitter to retransmit missing RLP frames using negative responses (NAKs). Because RLP error control protocols use retransmission mechanisms, RLP data transmissions typically suffer from different transmission delays from the sender to the receiver. An improved form of RLP, known as synchronized RLP (srlp), is one in which the transmitter or receiver does not send NAKs nor retransmits, as is well known in the art. The probability of frame errors in SRLP is greater than in RLP, but the transmission delay is kept at a minimum constant.

A remote network node such as a personal computer or laptop connected to a wireless Mobile Station (MS) that IS available for packet data may access the Internet via a wireless network in accordance with the IS-707 standard. Alternatively, a remote network node, such as a Web browser, may be built into the MS, making the PC more discretionary. An MS may include a variety of devices including but not limited to PC cards, Personal Data Assistants (PDAs), external or internal modems, or wireless telephones or terminals. The MS sends data through the wireless network for processing by a Packet Data Serving Node (PDSN). Typically, the PDSN maintains a PPP state for the connection between the MS and the wireless network. The PDSN is connected to an IP network, such as the Internet, and transports data between the wireless network and other entities or agents connected to the IP network. In this way, the MS can send and receive data to other entities on the IP network via the wireless data connection. The target on the IP network is also referred to essentially as a customer node. The interaction between the MS and the PDSN IS standardized by EIA/TIA/IS-835, entitled "Wireless IP Network Standard", published in 6 months of 2000 and referred to herein as "IS-835". Those skilled in the art will recognize that in some networks, the PDSN may be replaced by an interworking function (IWF).

In order to provide more sophisticated wireless network services, there is an assumption and need to provide different kinds of services simultaneously through the same wireless device. Including for example simultaneous voice and packet data services. For example, also including multiple categories of packet data services, such as simultaneous Web browsing and video conferencing. At the same time, advances in technology have increased the bandwidth available on a single wireless channel between a wireless device and a wireless network.

However, today's networks do not have the ability to support simultaneous packet data services with substantially different levels. For example, delay sensitive applications such as video conferencing and voice-over-IP applications are preferably sent without RLP retransmission to reduce the magnitude and variation of packet data delay across the network. Applications such as FTP, e-mail and Web browsing, on the other hand, are less sensitive to latency, so it is preferable to use RLP retransmission at the time of transmission. When applications require different levels of service, current wireless standards are suitable for supporting any one wireless application, but not multiple applications, requiring several levels of service in a single MS. Accordingly, there is a need in the art for a method of supporting multiple applications using different levels of service in a single MS.

Disclosure of Invention

Embodiments disclosed herein address the above stated needs by enabling a Mobile Station (MS) and a Radio Access Network (RAN) to establish a connection supporting multiple classes of service on a single IP address assigned to the MS. The embodiments described herein enable a data sender to use a single IP address for multiple packet data applications. The packet data generated by each of the multiple data applications is provided to a single point-to-point protocol (PPP) stack and a single high-level data link control (HDLC) framing layer to convert the packet data into a byte stream suitable for transmission over a Radio Link Protocol (RLP) connection. Each resulting multiple byte stream is then provided to one of multiple RLP connections with different retransmission and delay properties. The RLP connection selected to transmit data from each application is based on the service level best suited for that application.

The receiver receives data over multiple RLP connections and reassembles the byte stream into frames. The receiver may use multiple HDLC framing layers, one HDLC framing layer corresponding to one RLP connection. Alternatively, the receiver may use a single HDLC framing layer and multiple simple "deframer" layers. Each deframer layer corresponds to one RLP connection and searches each RLP byte stream for signature features that bound HDLC frames. The deframer layer does not delete the escape encoding of the HDLC but further provides HDLC stream data to the single HDLC layer in the form of complete, consecutive HDLC frames.

An aspect of the present invention relates to a method of providing a packet data service, including: establishing a single point-to-point protocol layer for communication between a mobile station and a wireless network; transmitting and receiving data over the single point-to-point protocol layer using at least two radio link protocol layers characterized by at least two different classes of service; establishing a single high level data link control layer between the point-to-point protocol layer and the at least two radio link protocol layers; and establishing a deframing layer between the advanced data link control layer and a first radio link protocol layer, the deframing layer configured to provide complete advanced data link control frames to the advanced data link control layer.

Another aspect of the present invention relates to a mobile station apparatus for providing a packet data service, comprising: a memory; and a processor configured to: establishing a single point-to-point protocol layer for the mobile station; transmitting and receiving data over the single point-to-point protocol layer using at least two radio link protocol layers characterized by at least two different classes of service; establishing a single high level data link control layer between the point-to-point protocol layer and the at least two radio link protocol layers; and establishing a de-framing layer between the advanced data link control layer and one of the at least two radio link protocol layers, the de-framing layer configured to provide complete advanced data link control frames to the advanced data link control layer.

Yet another aspect of the present invention relates to a wireless network apparatus comprising: a packet data serving node that extracts IP packet data from data received through a single advanced data link control layer associated with a single point-to-point protocol connection for a mobile station; and a packet control function module for establishing a first radio link protocol layer characterized by a first service class, establishing a second radio link protocol layer characterized by a second service class different from the first service class, deframing data received through the first radio link protocol layer to identify a first high-level data link control frame, deframing data received through the second radio link protocol layer to identify a second high-level data link control frame, providing the first high-level data link control frame to the single high-level data link control layer, and providing the second high-level data link control frame to the single high-level data link control layer after providing the first high-level data link control frame to the single high-level data link control layer.

Yet another aspect of the present invention relates to a mobile station apparatus comprising: a memory; and a processor configured to: establishing a single point-to-point protocol layer for communication between a mobile station and a wireless network; encapsulating an IP packet associated with a latency-sensitive application using the single point-to-point protocol layer to generate a first point-to-point protocol packet; encapsulating, using the single point-to-point protocol layer, an IP packet associated with a non-latency sensitive application to generate a second point-to-point protocol packet; transmitting the first peer-to-peer protocol packet to a wireless network through a low-latency wireless link protocol layer; and transmitting the second point-to-point protocol packet to the wireless network through the reliable radio link protocol layer; establishing a single high-level data link control layer between the single point-to-point protocol layer and the low-latency and reliable wireless link protocol layer; and establishing a deframing layer between the high level data link control layer and one of the low latency and reliable radio link protocol layers, the deframing layer configured to provide complete high level data link control frames to the high level data link control layer.

Yet another aspect of the present invention relates to a wireless network device, comprising: a packet control function module configured to establish a first radio link control layer characterized by a first service class, establish a second radio link control layer characterized by a second service class different from the first service class, deframe data received through the first radio link control layer to identify a first high-level data link control frame, deframe data received through the second radio link control layer to identify a second high-level data link control frame, provide the first high-level data link control frame to a single high-level data link control layer associated with a single point-to-point protocol connection to a mobile station, and provide the second high-level data link control frame to the single high-level data link control layer after providing the first high-level data link control frame to the single high-level data link control layer.

The word "exemplary" is used broadly throughout this application to mean "serving as an example, instance, or illustration. Any embodiment described as "exemplary embodiment" is not necessarily to be construed as preferred or advantageous over other embodiments described herein.

Brief description of the drawings

FIG. 1 shows an arrangement of protocol layers in accordance with an example embodiment;

FIG. 2 shows an arrangement of protocol layers in accordance with an alternative embodiment;

FIG. 3 is a schematic diagram of an exemplary Mobile Station (MS) device; and

FIG. 4 is a diagram of an exemplary wireless network device;

FIG. 5 is a flow diagram of an exemplary method for transmitting packet data over multiple RLP connections with different levels of service; and

fig. 6 is a flow diagram of an exemplary method for receiving packet data over multiple RLP connections with different levels of service.

Detailed description of the invention

By using separate point-to-point protocol (PPP) stacks for each application, a single wireless device can support multiple applications using different levels of service. This approach has several disadvantages. Supporting multiple PPP instances on a single Mobile Station (MS) would unnecessarily consume a large amount of data memory on the MS and the Packet Data Serving Node (PDSN).

In addition, if a Radio Link Protocol (RLP) session is established and used by an application requiring low latency, the RLP should be configured to operate without retransmission. This allows for low latency and is best suited for the above applications, but in this case the Link Control Protocol (LCP) and other configuration protocols that require PPP link establishment are handled without error control. This will result in an increase in frame error rate which can cause delays and even failure of PPP configuration before any application packet data can be sent.

The embodiments discussed below overcome these disadvantages by using a single PPP instance over multiple RLP instances between the MS and the wireless network. Fig. 1 shows an arrangement of protocol layers between a transmitter and a receiver of packet data using different concurrent service classes. In an exemplary embodiment, the transmitter maintains two Radio Link Protocol (RLP) layers (106 and 108), a high level data link control (HDLC) layer 104 and a point-to-point protocol (PPP) layer 102. Each RLP layer instance uses a different level of service (106 and 108). For example, if RLP_1S106 are configured to retransmit frames based on NAK frames received by the receiver, RLP_2S108 are configured without retransmission. In other words, RLP_1S106 provide increased reliability by using an error control protocol, RLP_2S108 provide unreliable transmission but with a fixed, minimal transmission delay. Having a profile like RLP_1S106 are referred to herein simply as "reliable". Also, having a shape like RLP_2S108 are referred to herein as "low latency". Although the exemplary embodiment described herein uses only two classes of service, implementations using a greater number of different classes of service are also envisioned and should be considered within the scope of the embodiments described herein. For example, the transmitter and receiver may each use an additional third RLP layer to provide an intermediate level of service with reliability between "reliable" and "low latency".

In an exemplary embodiment, the receiver also maintains two receiving RLP instances (116 and 118) corresponding to RLP instances (106 and 108) of the same service level in the transmitter. Such as RLP_1S106Providing reliable service level, RLP_1R116 are configured to a reliable service level. Thus, when RLP is used_1RIn response to detection of sequence number interruption in received RLP frames by layer 116, the RLP_1R116 sends a NAK frame to request retransmission. If an RLP NAK frame is received, the RLP_1S106 retransmit the requested frame from its retransmission buffer. On the other hand, if RLP_2S108 configured to a low latency class of service, the RLP is configured to operate regardless of whether there is a break in the frame sequence number_2R118 do not send NAK frames. In fact, RLP_2S108 and RLP_2R118 may completely ignore the frame sequence numbers of the transmitted RLP frames to leave more room for data payload. In addition, RLP_2S108 need not maintain a retransmission buffer for previously transmitted frames, thus saving memory in the transmitter. Also, RLP_2R118 need not maintain a re-ordered buffer, which saves memory in the receiver.

PPP in a transmitter_SLayer 102 encapsulates the IP packet data in PPP frames. In one exemplary embodiment, PPP_SLayer 102 increases packet data throughput by performing IP header compression, such as the well-known Van-jacobsen (vj) header compression. VJ header compression may result in the loss of some header information that is useful for multiplexing PPP packets between multiple RLP layers (106 and 108). In one exemplary embodiment, PPP_SLayer 102 provides the entire PPP packet data to HDLC_SLayer 104 and also provides information that may be used to determine which RLP layer to use to transmit data frames. In one exemplary embodiment, PPP_SLayer 102 is provided for each HDLC_SThe PPP packet data of layer 104 provides a service level identifier or an RLP instance identifier. HDLC_SLayer 104 adds identifier characters between PPP packet data and for data received from PPP_SEach PPP packet data of layer 102 adds a cyclic redundancy check sum (CRC). HDLC_SLayer 104 also performs HDLC escape to ensure that the flag or HDLC control word does not appear in the data of a single frame. HDLC_SLayer 104 typically includes at least two by using oneAn escape sequence of characters replaces each index or control character to implement HDLC escape.

The receiver in fig. 1 has separate HDLC layers (112 and 114) for each RLP instance (116 and 118). The bytes in the RLP frames received by each RLP instance (116 and 118) appear in the corresponding HDLC layer instance (112 and 114). Each HDLC layer instance (112 and 114) places escape sequences separately in the input data stream and converts each escape sequence back to the original data in the transmitted frame. The HDLC layer instances (112 and 114) also check the received CRC in the received frame to determine if the received frame has a communication error. Frames with incorrect CRC are discarded and frames with correct CRC are sent up to the next protocol layer (PPP)_R)110。

Fig. 2 shows another arrangement of protocol layers. The protocol layer arrangement of the transmitter in fig. 2 is the same as that of the transmitter in fig. 1. However, in the receiver, a single HDLCR layer 212 is used instead of one HDLC for each RLP instance_RAnd (3) a layer. The deframer layers (214 and 220) are inserted into the RLP layers (218 and 220) and the HDLC_RBetween the layers 212. The purpose of the deframers (214 and 220) is to ensure that only complete HDLC frames are delivered to the HDLC_RLayer 212. HDLC is not required since only complete HDLC frames are delivered_RLayer 212 distinguishes, or recombines, the data in multiple HDLC frames. For a complete frame, HDLC_RLayer 212 deletes escape sequences and checks the CRC. If the CRC is deemed correct, HDLC_RLayer 212 completely transmits the PPP frame to PPP_RLayer 210. If the CRC is incorrect, the HDLC_RLayer 212 discards the erroneous frame data.

One benefit of using the deframer layers (214 and 220) is that the receiver is enabled to support multiple instances of RLP (218 and 216) without alignment to HDLC_RThe implementation of the layer 212 is subject to any change. HDLC_RLayer 212 need not even know that the received bytes were received over two different RLP connections. In the process of HDLC_RThe independence of the implementation is particularly important in network implementations where the layer 212 and the RLP protocol layers are located in different physical devices. For example, HDLC_RThe layer may exist in the labelQuasi-packet routers, while the RLP layer may exist in the packet data control function (PCF) of the Radio Access Network (RAN) in the wireless network. The use of the deframer layer makes it possible to support multiple RLP layers and multiple classes of service without changing the software of a standard packet router.

Fig. 3 illustrates an exemplary Mobile Station (MS) supporting multiple classes of service as discussed above. Control processor 302 establishes a wireless connection through illustrated wireless modem 304, transmitter 306, and antenna 308. In an exemplary embodiment, the wireless modem 304 and transmitter 306 operate as described for cdma 2000. Alternatively, wireless modem 304 and transmitter 306 may operate in accordance with some other wireless standard, such as IS-95, W-CDMA, or EDGE.

Control processor 302 is coupled to memory 310, and memory 310 stores code and instructions that instruct control processor 302 to establish and use the protocol layers shown in fig. 1-2. Memory 310 may include RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other storage medium or computer-readable medium known in the art.

In an exemplary embodiment, control processor 302 uses a portion of memory 310 as a memory buffer (312 and 314) required to operate multiple RLP layers. For example, if RLP₁Buffer 312 corresponds to a reliable RLP connection that will include a retransmit buffer for transmitted RLP data and a reorder buffer for received RLP data. If RLP₂Buffer 314 corresponds to a low latency RLP connection, then the RLP₂Buffer 314 requires neither a retransmit buffer nor a reorder buffer. Because these two buffers are not needed, RLP₂Buffer 314 ratio RLP₁Buffer 312 occupies less memory. Although illustrated as unconnected, the buffers (312 and 314) may also overlap if some of the data structures are common in multiple RLP implementations.

Fig. 4 illustrates an exemplary wireless communication network connected to a packet network, such as the Internet 416. The wireless communication network includes RAN 412 and PDSN 414. RAN 412 further includes a selector 402 coupled to one or more base stations (not shown). The selector 402 in the RAN 412 is typically a subsystem of a Base Station Controller (BSC), not shown here. All wireless data sent to or received from the MS will be routed through the selector. In addition to the selector 402, the RAN 412 also includes a packet data control function (PCF) 404. For the packet data service option, the selector will receive packet data from the MS for transmission by PCF 404, PCF 404 further comprising control processor 406 and memory 418.

Memory 418 contains code and instructions that direct control processor 406 to establish and use the protocol layers shown in fig. 1-2. Memory 418 includes RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium or computer-readable medium known in the art.

In an exemplary embodiment, control processor 406 establishes multiple buffers (408 and 410) in memory 418 that are used for the various RLP connections established for the plurality of mobile stations. In one exemplary embodiment, RLP₁The pool of buffers 408 includes retransmission and reordering buffers for reliable RLP instances. Another RLP₂The pool of buffers 410 is for low latency RLP instances and therefore does not include retransmission and reordering buffers. Control processor 406 may assign more than one RLP instance for a single MS. For example, an RLP₁Buffer and an RLP₂The buffer may be allocated to a single MS running a combined delay-sensitive and non-delay-sensitive application.

The control processor 406 is also connected to the PDSN 414. In an exemplary embodiment, when the MS sends IP packet data to packet network 416, control processor 406 receives RLP frames from selector 402 and extracts a byte stream from the RLP frames using an associated RLP buffer (408 or 410). The control processor 406 then sends these bytes to the PDSN 414, and the PDSN 414 extracts the complete IP packet data (those with the correct CRC value) from the byte stream in accordance with the HDLC protocol. PDSN 414 then transmits the resulting IP packet data to packet network 416. If the PDSN 414 maintains a single HDLC connection for multiple RLP connections for a single MS, the control processor 406 performs de-framing before sending bytes from the RLP frames to the PDSN 414. The result of the deframing is that the entire HDLC frame is transmitted by the control processor 406 to the PDSN 414. In other words, the control processor 406 ensures that data in HDLC frames received from one RLP link is not mixed with data in HDLC frames received from another RLP link. Deframing will allow for better resource utilization on the basis that existing PDSNs, which cannot assign more than one PPP/HDLC to one IP address, can be used.

When packet network 416 sends packet data to the MS, the packet data is first received by PDSN 414. In an exemplary embodiment, the PDSN 414 encapsulates the IP datagram addressed to the MS into a PPP packet data and uses HDLC framing to convert the resulting PPP frames into a byte stream. In an exemplary embodiment, PDSN 414 assigns a single HDLC instance to a single MS and uses the HDLC instance to HDLC frame any IP packet data addressed to the MS. In an alternative embodiment, PDSN 414 may assign multiple HDLC instances to a single MS such that each HDLC instance corresponds to a single RLP connection with the MS.

The connections between the PDSN 414 and the network 416, between the PDSN 414 and the control processor 406, and between the control processor 406 and the selector 402 may use any one of a number of interfaces including ethernet, T1, ATM, or other fiber optic, wired, or wireless interfaces. In the exemplary embodiment, the connection between control processor 406 and memory 418 is typically a direct hardware connection, such as a memory bus, but may be one of the other types of connections discussed above.

Fig. 5 is a flow diagram of an exemplary method for transmitting packet data over multiple RLP connections with different grades of service. In an exemplary embodiment, the control processor of the sending device (302 in FIG. 3 or 406 in FIG. 4) uses the method described in FIG. 5. In step 502, the sender encapsulates the IP packet data to be sent into a PPP packet. In an exemplary embodiment, IP header compression, such as Van-Jacobsen (VJ) header compression, is also performed in step 502. In step 504, the sender next converts the PPP packets into a byte stream according to the HDLC protocol. Specifically, each PPP packet is converted into one HDLC frame. One or more flag characters are inserted between HDLC frames of the byte stream, and the flag and control characters present in each frame are replaced by escape sequences. An example of the most common HDLC exit possible is to replace the flag sequence octet 0x7e (16 system) with two octets 0x7d0x5e (16 system) and the octet 0x7d (16 system) with two octets 0x7d0x5d (16 system). Also at step 504, a CRC is calculated for each frame and inserted into the end of the frame (before the index character indicating the end of the frame). In step 506, the transmitter determines which set of available service classes should be used to transmit frame data based on the type of packet data. If the IP packet data to be transmitted uses a non-delay sensitive application such as FTP or TCP, it is transmitted using reliable RLP (with retransmission and reordering) at step 508. Likewise, any packet data that is not an IP packet, but is still non-delay sensitive (such as IPCP or LCP packets), is also sent using reliable RLP at step 508. Delay sensitive type packets, such as Real Time Protocol (RTP) packets for video related services, are transmitted using low delay RLP at step 510. As discussed above, low latency RLP does not transmit or require retransmission of RLP frames that were lost due to communication errors. Although two service levels are shown in the exemplary embodiment of fig. 5, those skilled in the art will recognize that other systems may use more than two different service levels without departing from the scope of the description of the present embodiment. For example, at step 506, the transmitter may choose to transmit several types of packet data over an RLP connection with an intermediate level of reliability.

Fig. 6 is a flow diagram of an exemplary method for receiving packet data via RLP connections having different classes of service. In an exemplary embodiment, the control processor of the receiving device (302 in FIG. 3 or 406 in FIG. 4) uses the method illustrated in FIG. 6. At step 602, the receiver processes RLP frames received over one or more RLP connections. In one of the above described exemplary embodiments, the RLP frames are received over two types of RLP connections, a low latency connection and a reliable connection.

As described in the aforementioned IS-707, RLP frames received over a reliable RLP connection have sequence numbers that are used by the receiver to reorder the frames and retransmit lost frames. For example, if an RLP frame whose sequence number is "7" is lost due to a communication error, the receiver sends a NAK frame to request retransmission of that frame. When a retransmitted frame is received, the data carried in the frame is used to complete the data byte stream before providing subsequent data bytes to the HDLC layer. As a result, the stream of data bytes extracted from RLP frames of a reliable RLP connection is typically gapless compared to frames transmitted by the transmitter. The cost of avoiding gaps is that the data has a variable delay.

Conversely, when an RLP frame on a low-latency RLP link is lost due to a communication error, retransmission is not required or performed. Any data bytes carried in the missing RLP frame will be ignored as they appear in the data byte stream at the HDLC layer of the receiver. In other words, the loss of one RLP frame on a low latency RLP link always causes gaps between the data byte stream at the receiver and transmitted by the transmitter. However, the low-latency RLP protocol has a fixed small latency, making it well suited for transmitting latency sensitive type of packets, such as RTP packets.

In the exemplary embodiment depicted in fig. 2, the receiver uses deframers (214 and 220 in fig. 2) received over multiple RLP connections (218 and 216 in fig. 2) to provide complete HDLC frame data to a single HDLC protocol layer (212 in fig. 2). In fig. 6, deframing is performed in step 604. At step 606, the HDLC protocol layer (212 in fig. 2) deletes the HDLC escape sequence inserted by the transmitter and checks the CRC of each HDLC frame. Any HDLC frames with incorrect CRCs are deleted by the receiver in step 606. The resulting PPP frame is then provided by the HDLC protocol layer to the PPP layer. At step 608, the PPP layer de-encapsulates the received packet data, removing the PPP header and any other changes made by the sender. Also at step 608, if the sender compresses the IP header of the received packet data (e.g., using VJ header compression), the IP header will expand to its original size and content. The decapsulated packet data is then routed in step 610. Although the embodiments described above primarily discuss encapsulated IP packets, PPP and HDLC may also be used to transmit packets for other protocols such as IPX or LCP.

In an exemplary embodiment using the deframers (214 and 220 in fig. 2), steps 602 and 604 are performed by a control processor (406 in fig. 4) in the RAN (412 in fig. 4) and steps 606, 608 and 610 are performed by the PDSN (414 in fig. 4). In an alternative embodiment as shown in fig. 1, the PDSN (414 in fig. 4) assigns multiple HDLC layers (112 and 114 in fig. 1) to a single MS. In this embodiment, the receiver does not perform deframing and step 604 is omitted. At step 602, each RLP layer (116 and 118 in fig. 1) provides data extracted from a received RLP frame directly to its corresponding HDLC layer (112 and 114, respectively, in fig. 1).

Thus, described herein is a method and apparatus for providing multiple quality of service levels in a wireless packet data service connection. Those of skill in the art would understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof. Those skilled in the art will also recognize that the PDSN in the above-described embodiment may also be replaced with an interworking function (IWF) without departing from the scope of the embodiment.

Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations 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 their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

The various illustrative logical blocks, modules, and circuits described in connection with the embodiments disclosed herein may be implemented or performed with 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, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microprocessor, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or other configuration.

The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hardware, a removable disk, a CD-ROM, or other form of storage medium or computer-readable medium known in the art. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may be disposed in a mobile station. In the alternative, the processor and the storage medium may reside as discrete components in a mobile station.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. This way. The present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (16)

1. A method of providing packet data services, comprising:

establishing a single point-to-point protocol layer for communication between a mobile station and a wireless network;

transmitting and receiving data over the single point-to-point protocol layer using at least two radio link protocol layers characterized by at least two different classes of service;

establishing a single high level data link control layer between the point-to-point protocol layer and the at least two radio link protocol layers; and

establishing a deframing layer between the advanced data link control layer and a first radio link protocol layer, the deframing layer configured to provide complete advanced data link control frames to the advanced data link control layer.

2. The method of claim 1, further comprising:

establishing a first buffer, the size of the first buffer depending on the first service level; and

a second buffer is established, the size of the second buffer being dependent on the second class of service.

3. The method of claim 2, wherein the first buffer includes a retransmit and reorder buffer, and the second buffer does not include a retransmit and reorder buffer.

4. The method of claim 1, wherein the at least two radio link protocol layers characterized by at least two different service levels comprise a first radio link protocol layer characterized by a first service level and a second radio link protocol layer characterized by a second service level.

5. The method of claim 1, further comprising establishing a buffer for each of the at least two radio link protocol layers, wherein the size of each buffer is dependent on the class of service of the corresponding radio link protocol layer.

6. A mobile station apparatus for providing a packet data service, comprising:

a memory; and

a processor configured to:

establishing a single point-to-point protocol layer for the mobile station;

transmitting and receiving data over the single point-to-point protocol layer using at least two radio link protocol layers characterized by at least two different classes of service;

establishing a single high level data link control layer between the point-to-point protocol layer and the at least two radio link protocol layers; and

establishing a de-framing layer between the advanced data link control layer and one of the at least two radio link protocol layers, the de-framing layer configured to provide complete advanced data link control frames to the advanced data link control layer.

7. The mobile station apparatus of claim 6, further comprising a radio modem that modulates radio link protocol frames generated by the first and second radio link protocol layers.

8. The mobile station apparatus of claim 6, further comprising a CDMA radio modem that modulates radio link protocol frames generated by the first and second radio link protocol layers.

9. The mobile station apparatus of claim 6, wherein the different classes of service include a reliable class of service and a low latency class of service.

10. The mobile station device of claim 6, wherein the processor is further configured to: establishing a buffer for each of the at least two radio link protocol layers, the size of each buffer being dependent on the service level of the corresponding radio link protocol layer.

11. The mobile station apparatus of claim 10, wherein each buffer comprises retransmission and reordering buffers only if the corresponding radio link protocol layer is a reliable radio link protocol layer.

12. A wireless network device includes:

a packet data serving node that extracts IP packet data from data received through a single advanced data link control layer associated with a single point-to-point protocol connection for a mobile station; and

a packet control function module for establishing a first radio link protocol layer characterized by a first service level, establishing a second radio link protocol layer characterized by a second service level different from the first service level, deframing data received via the first radio link protocol layer to identify a first high-level data link control frame, deframing data received via the second radio link protocol layer to identify a second high-level data link control frame, providing the first high-level data link control frame to the single high-level data link control layer, and providing the second high-level data link control frame to the single high-level data link control layer after providing the first high-level data link control frame to the single high-level data link control layer.

13. A mobile station apparatus, comprising:

a memory; and

a processor configured to:

establishing a single point-to-point protocol layer for communication between a mobile station and a wireless network;

encapsulating an IP packet associated with a latency-sensitive application using the single point-to-point protocol layer to generate a first point-to-point protocol packet;

encapsulating, using the single point-to-point protocol layer, an IP packet associated with a non-latency sensitive application to generate a second point-to-point protocol packet;

transmitting the first peer-to-peer protocol packet to a wireless network through a low-latency wireless link protocol layer; and

transmitting the second point-to-point protocol packet to the wireless network through the reliable radio link protocol layer;

establishing a single high-level data link control layer between the single point-to-point protocol layer and the low-latency and reliable wireless link protocol layer; and

establishing a deframing layer between the high level data link control layer and one of the low latency and reliable radio link protocol layers, the deframing layer configured to provide complete high level data link control frames to the high level data link control layer.

14. The mobile station device of claim 13, wherein the processor is further configured to:

before transmitting the first point-to-point protocol packet, translating the first point-to-point protocol packet into a first high-level data link control frame using the high-level data link control layer; and

the second point-to-point protocol packet is translated into a second high-level data link control frame using the high-level data link control layer before sending the second point-to-point protocol packet.

15. A wireless network device, comprising:

a packet control function module configured to establish a first radio link control layer characterized by a first service class, establish a second radio link control layer characterized by a second service class different from the first service class, deframe data received through the first radio link control layer to identify a first high-level data link control frame, deframe data received through the second radio link control layer to identify a second high-level data link control frame, provide the first high-level data link control frame to a single high-level data link control layer associated with a single point-to-point protocol connection to a mobile station, and provide the second high-level data link control frame to the single high-level data link control layer after providing the first high-level data link control frame to the single high-level data link control layer.

16. The wireless network device of claim 15, further comprising a packet data serving node configured to extract IP packets from data received over a single high level data link control layer.