(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2005/0238051A1
`(43) Pub. Date:
`Oct. 27, 2005
`Yi et al.
`
`US 2005O238051A1
`
`(54) APPARATUS AND METHOD FOR
`TRANSMITTING DATA BLOCKS BASED ON
`PRIORITY
`(75) Inventors: Seung-June Yi, Seoul (KR);
`Young-Dae Lee, Gyeonggi-do (KR);
`Sung-Duck Chun, Seoul (KR)
`Correspondence Address:
`LEE, HONG, DEGERMAN, KANG &
`SCHMADEKA
`14th Floor
`801 S. Figueroa Street
`Los Angeles, CA 90017 (US)
`(73) Assignee: LG Electronics Inc.
`(21) Appl. No.:
`11/097,762
`(22) Filed:
`Mar. 31, 2005
`(30)
`Foreign Application Priority Data
`
`Mar. 31, 2004 (KR)............................ 10-2004-0O22435
`
`
`
`Publication Classification
`
`(51) Int. CI.' ........ H04J 3/22; H04J 3/16; H04Q 7/00;
`HO4L 12/26; G01 R 31/08;
`G08C 15/00; G06F 11/00;
`HO4J 3/14; HO4J 1/16; HO4L 1/00
`
`(52) U.S. Cl. ........................... 370/469; 370/328; 370/229
`
`(57)
`
`ABSTRACT
`
`A particular protocol layer of the transmitting side (trans
`mitter) initially receives service data units (SDUs) having
`the same priority through a single Stream from an upper
`layer, processes these SDUS to generate protocol data units
`(PDUs) having different priorities, and uses respectively
`different transmission methods to transmit the generated
`PDUs over a radio interface in order to guarantee their
`respectively different quality of Service (QoS) requirements.
`
`CORE NETWORK
`
`1 OO
`
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`Patent Application Publication Oct. 27, 2005 Sheet 1 of 10
`
`US 2005/0238051A1
`
`FIG. 1
`
`
`
`CORE NETWORK
`
`OO
`
`
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`Patent Application Publication Oct. 27, 2005 Sheet 2 of 10
`
`US 2005/0238051A1
`
`FIG. 2
`
`Control Plane
`
`User Plane
`
`
`
`TT III
`
`I
`
`RRC
`(Layer 3)
`
`Radio
`Bearers
`
`PDCP
`(Layer 2)
`
`BMC
`(Layer 2)
`
`Logical Channel
`MAC
`(Layer 2)
`
`Transport Channel
`PHY
`(Layer 1)
`
`
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`Patent Application Publication Oct. 27, 2005 Sheet 3 of 10
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`US 2005/0238051A1
`
`FIG. 3
`
`Node B RNC
`
`lu Bearer (QoS-lu)
`
`MSC
`SGSNIGGSN
`
`FIG. 4
`
`Header
`size
`
`
`
`Full Header
`Compressed Header
`
`
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`Patent Application Publication Oct. 27, 2005 Sheet 4 of 10
`FIG. 5
`
`US 2005/0238051A1
`
`IP Packet
`
`Y
`Compressed
`p
`M LOW
`2 2 Y. Header Packet
`YYYYA
`2 LOW
`Full Header
`HIGH
`Packet
`
`
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`Patent Application Publication Oct. 27, 2005 Sheet 5 of 10
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`US 2005/0238051A1
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`FIG. 6
`
`
`
`Compressed
`2 Header Packet
`
`Full Header
`Packet
`
`
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`Patent Application Publication Oct. 27, 2005 Sheet 6 of 10
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`US 2005/0238051A1
`
`FIG. 7
`
`
`
`
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`Patent Application Publication Oct. 27, 2005 Sheet 7 of 10
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`US 2005/0238051A1
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`FIG. 8
`
`HIGH
`
`MID
`LOW
`
`LOW
`
`HIGH
`
`PHY
`
`Power controller
`
`
`
`
`
`
`
`
`
`Power Level
`
`
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`Patent Application Publication Oct. 27, 2005 Sheet 8 of 10
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`US 2005/0238051A1
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`FIG. 9
`
`
`
`MD
`
`Power Level
`
`
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`Patent Application Publication Oct. 27, 2005 Sheet 9 of 10
`FIG. 10
`
`US 2005/0238051A1
`
`
`
`NA
`
`UTRAN
`
`4' 020
`
`1030
`
`M
`
`Momoyl 1028-2
`Memory
`
`
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`Patent Application Publication Oct. 27, 2005 Sheet 10 of 10
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`US 2005/0238051A1
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`FIG. 11
`
`1100 O
`
`1135
`
`
`
`
`
`Receiver
`
`RF Module
`ransmitte
`
`
`
`
`
`
`
`
`
`1150
`
`1145
`
`-CH Management
`
`DSP/Microprocessor
`1111 1113
`
`Monitoring
`circuits
`
`1130
`
`1125
`
`
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`US 2005/0238051A1
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`Oct. 27, 2005
`
`APPARATUS AND METHOD FORTRANSMITTING
`DATA BLOCKS BASED ON PRIORITY
`
`CROSS REFERENCE TO RELATED
`APPLICATIONS
`0001 Pursuant to 35 U.S.C. S 119(a), the present appli
`cation claims the benefit of earlier filing date and right to
`priority to Korean application number 10-2004-022435,
`filed Mar. 31, 2004; the disclosure of which is incorporated
`herein in its entirety.
`
`BACKGROUND AND SUMMARY
`0002 The present invention relates to an apparatus and
`method for transmitting data blockS based on priority from
`a transmitter in a UMTS (Universal Mobile Telecommuni
`cations System) type IMT-2000 system, and in particular, to
`an apparatus and method for transmission whereby a par
`ticular protocol layer determines the priority of each data
`block among the data blockS received from an upper layer
`through a single data Stream, transferS the determined pri
`orities together with the data blocks to a lower layer through
`a single data Stream, and the lower layer receiving the data
`blocks with their priorities guarantees the respective quality
`of Service (QoS) according to each respective priority for
`each data block for transmission over the radio interface, to
`thus guarantee a respectively different QoS for each data
`block within a Single data Stream having the same QoS being
`guaranteed.
`0003) A universal mobile telecommunication system
`(UMTS) is a third generation mobile communications sys
`tem that has evolved from the European Global System for
`Mobile communications (GSM) that aims to provide an
`improved mobile communications Service based upon a
`GSM core network and wideband code division multiple
`access (W-CDMA) wireless connection technology.
`0004 FIG. 1 illustrates an exemplary basic architecture
`of a UMTS network. As shown in FIG. 1, the UMTS is
`roughly divided into a terminal 100 (mobile station, user
`equipment (UE), etc.), a UMTS Terrestrial Radio Access
`Network (UTRAN) 120, and a core network (CN) 130. The
`UTRAN 120 includes one or more radio network Sub
`systems (RNS) 125. Each RNS 125 includes a radio network
`controller (RNC) 123, and a plurality of base stations
`(Node-Bs) 121 managed by the RNC 123. One or more cells
`exist for each Node B 121.
`0005 The RNC 123 handles the assigning and managing
`of radio resources, and operates as an access point with
`respect to the core network 130. The Node-Bs 121 receive
`information sent by the physical layer of the terminal 100
`through an uplink, and transmit data to the terminal through
`a downlink. The Node-BS 121, thus, operate as access points
`of the UTRAN 120 for the terminal 100. Also, the RNC 123
`allocates and manages radio resources and operates as an
`access point with the core network 130. Between various
`network Structure elements, there exists an interface that
`allows data to be exchanged for communication therebe
`tWeen.
`0006 FIG. 2 illustrates a radio interface protocol archi
`tecture that exists in the mobile terminal and in the UTRAN
`as one pair, for handling data transmissions via the radio
`interface. Regarding each radio protocol layer, the first layer
`
`(Layer 1) is a physical layer (PHY) that serves the purpose
`of transmitting data over the radio interface by using various
`radio transmission techniques. The PHY layer is connected
`with an upper layer, the MAC layer via transport channels,
`which include a dedicated transport channel and a common
`transport channel depending upon whether that channel is
`shared or not.
`0007. In the second layer (Layer 2), a medium access
`control (MAC) layer, a radio link control (RLC) layer, a
`packet data convergence protocol (PDCP) layer and abroad
`cast/multicast control (BMC) layer exist. The MAC layer
`Serves the purpose of mapping various logical channels to
`various transport channels, as well as performing logical
`channel multiplexing for mapping a plurality of logical
`channels to a single transport channel. The MAC layer is
`connected to a higher layer (e.g., the RLC layer) via logical
`channels, and these logical channels are divided into control
`channels that transmit control plane information and traffic
`channels that transmit user plane information.
`0008. The RLC layer handles the guaranteeing of the
`quality of service (QoS) of each radio bearer (RB) and the
`transmission of the corresponding data thereof. To guarantee
`the unique QoS of a radio bearer, the RLC layer has therein
`one or two independent RLC entities for each radio bearer,
`and provides three types of RLC modes, a transparent mode
`(TM), an unacknowledged mode (UM), and an acknowl
`edged mode (AM), in order to Support the various QoS.
`Also, the RLC layer adjusts the data Size accordingly Such
`that a lower layer may transmit data over the radio interface,
`by performing Segmentation and concatenation on the data
`received from an upper layer.
`0009. The PDCP layer is located above the RLC layer
`and allows data that is transmitted by using Internet Protocol
`(IP) packets, such as IPv4 or IPv6, to be effectively trans
`mitted over a radio interface having a relatively Smaller
`bandwidth. For this purpose, the PDCP layer performs a
`header compression function, whereby only the absolutely
`necessary data in the header portion of the data are trans
`mitted, in order to increase transmission efficiency over the
`radio interface. Because header compression is its basic
`function, the PDCP layer only exists in the PS (packet
`switched) domain, and a single PDCP entity exists per each
`radio bearer (RB) for providing effective header compres
`sion function with respect to each PS service.
`0010 Additionally, in the second layer (L2), a BMC
`(Broadcast/Multicast Control) layer exists above the RLC
`layer for performing the functions of Scheduling cell broad
`cast messages and broadcasting to terminals located in a
`particular cell.
`0011 The radio resource control (RRC) layer located at
`the lowest portion of the third layer (L3) is only defined in
`the control plane, for controlling the parameters of the first
`and Second layers and for controlling the transport channels
`and the physical channels in relation to the establishment,
`the re-configuration, and the releasing of the radio bearers
`(RBs). Here, the RB refers to a logical path provided by the
`first and Second layers of the radio protocol for data transfer
`between the terminal and the UTRAN. And in general, the
`establishment of a radio bearer (RB) refers to regulating the
`protocol layerS and the channel characteristics of the chan
`nels required for providing a specific Service, as well as
`Setting their respective Specific parameters and operation
`methods.
`
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`0012 Hereafter, the establishment of a radio bearer
`according to a quality of Service (QoS) will be explained.
`QoS refers to the quality of Service that the end-user notices
`upon being provided with a particular Service. Various
`factors affect the QoS, Such as delay time, error ratio, bit
`rate, and the like. In UMTS, an appropriate QoS is deter
`mined according to the type of Service that is to be provided
`to the end-user. Here, the appropriate QoS refers to a
`minimum QoS that allows the end-user to be provided with
`the Service, and the reason for Setting a minimum QoS is to
`allow the service to be provided to a plurality of users.
`Namely, because radio resources are limited, providing a
`Service using a high QoS to a particular user means that a
`large amount of radio resources are allocated to that par
`ticular user, and thus the total number of users to which
`service can be provided by the UMTS is decreased when
`considering the Overall cell in which Service is being pro
`vided.
`0013. In UMTS, as the entity that determines the QoS for
`a certain type of service, a MSC (Mobile Switching Center)
`is used for CS (circuit Switched) services, while a SGSN
`(Serving GPRS Supporting Node) or a GGSN (Gateway
`GPRS Supporting Node) is used for PS (packet switched)
`Services, and these entities exist within the core network
`(CN). When the QoS determining entities receive a request
`for a particular Service from a terminal or an entity outside
`of the UMTS, an overall QoS is determined between the
`terminal and the QoS determining entity.
`0014 FIG. 3 depicts how the QoS between the terminal
`(UE) the Node B/RNC and the MSC (SGSN/GGSN) are
`defined. In FIG. 3, the QoS is separately established by
`sections, which can be broadly divided into a “lu section”
`that is a wired (wireline) interface between the MSC (or the
`SGSN/GGSN) to the Node B/RNC, and a “Uu section” that
`is a wireless (radio) interface between the Node B/RNC and
`the terminal. Also, the lu Section has a lu Bearer and the Uu
`Section has a radio bearer (RB) established, respectively, for
`providing Services having an appropriate QoS. The overall
`QoS between the terminal and the MSC (or the SGSN/
`GGSN) is determined by the sum of the quality of service for
`the lu interface (“QoS-lu') and the quality of service for the
`Uu interface (“OoS-Uu'). As the wireless interface has a
`more disadvantageous environment when compared to that
`of the wired interface, the overall QoS mostly depends upon
`the OOS-Uu.
`0.015 The details of the QoS and bearer configuration
`procedures will be explained with respect to a VoIP (Voice
`over Internet Protocol) service as being a representative
`example of a PS service. First, assuming that the SGSN
`received a request for VoIP service from a terminal, the
`SGSN determines an appropriate QoS for providing the
`requested VoIP service by considering the priority and/or
`capabilities of the terminal and/or considering various types
`of available resources. Also, it is assumed that the SGSN
`determined the overall QoS with the following parameters:
`Delay=200 ms; Error Ratio=10°; Bit Rate=36 kbps. Based
`upon this overall QoS, the SGSN then determines the QoS
`for each Section. Here, because the wired interface generally
`has a more advantageous environment compared to that of
`the wireleSS interface, it does not greatly affect the overall
`QoS. Namely, the wired interface has a delay of less than a
`few milliseconds (ms), an error ratio of less than 10 and a
`bit rate of Several to Several hundred megabits per Second
`
`(Mbps), thus most of the values for the overall QoS are
`directly applicable to the QoS-Uu. Generally, the error rate
`and bit rate of the overall QoS are directly applied to the
`QoS-Uu, and a delay value that excludes a few milliseconds
`(ms) needed for the core network protocol to process data is
`applied. Thus, for this situation, it is assumed that the SGSN
`determined the QoS-Uu to have the following parameters:
`Delay=180 ms; Error Ratio=10°; Bit Rate=36 kbps. Then,
`the SGSN informs this determined QoS-Uu to the RNC, and
`the RNC configures an appropriate radio bearer (RB) in
`accordance thereto.
`0016. The RNC configures the RB based upon the QoS
`Uu informed by the SGSN. More accurately, the RRC layer,
`which is a radio protocol layer within the RNC, configures
`the RB. As explained previously, the RB refers to a logical
`path provided by the first and second layers of the radio
`protocol, and the data transmitted through the RB are
`basically guaranteed the quality corresponding to the QoS
`Uu. In order to configure an RB that satisfies the QoS-Uu,
`the RRC layer of the RNC configures the first and second
`layers of the radio protocol, and various characteristics,
`operation procedures, parameters, and the like for each of
`the channels. For example, with respect to the PDCP layer,
`the type of header compression method to be used, etc. are
`determined. With respect to the RLC layer, the type of
`operation mode to be used, the maximum data Storage time
`to be used, the size of the RLC PDU (protocol data unit) to
`be used, various timer values and protocol parameter values
`to be used, etc. are determined. With respect to the MAC
`layer, the type of channel mapping to be used, the method of
`channel multiplexing to be used, the method of priority
`processing to be used, how to perform transmission format
`combinations, etc. are determined. With respect to the PHY
`(physical) layer, the method of modulation to be used, the
`coding methods to be used, the type of CRC (cyclic redun
`dancy check) to be used, the transmission power level to be
`used, the types of physical channels to be used, etc. are
`determined.
`0017. After the RRC of the RNC determines all of the
`aspects of the RB, the first and second layers of the RNC are
`established according to the determined aspects, and Simul
`taneously informs these aspects to the RRC of the terminal
`to allow the first and second layers of the terminal to be
`established according to these aspects. When the RB is
`established in this manner, a logical path between the
`terminal and the RNC is formed, and thereafter, data is
`transmitted according to the determined path. Here, as
`explained before, because a Single RB guarantees a Single
`QoS-Uu, the data transmitted through the same RB are all
`guaranteed the same QoS-Uu.
`0018. In the related art, because a single RB guarantees
`a single QoS (QoS-Uu), the data transmitted through the
`same RB is guaranteed the same QoS. However, there are
`certain situations where the data transmitted via a Single RB
`will have respectively different priorities according to the
`processing techniques of the radio protocol layers, thus
`requiring respectively different QoS to be guaranteed. The
`header compression performed at the PDCP layer is an
`example of one Such situation.
`0019. The header compression technique utilizes the fact
`that many portions of the IP headers of IP packets that are
`part of the same packet Stream do not change at all or do not
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`change very often. The fields that do not change are Stored
`in the format of context within a compressor of the trans
`mitting Side (i.e., transmitter) and within the decompressor
`of the receiving side (i.e., receiver), and the overhead of an
`IP header can be reduced by only transmitting those fields
`that have changed after the context has been formed. During
`the initial Stages of header compression, because the com
`preSSor transmits full header packets to the decompressor in
`order to form the context with respect to the corresponding
`packet stream, there is no gain (advantage) of using header
`compression. But after the context is formed in the decom
`preSSor, the compressor only transmits compressed header
`packets, and thus the gain (advantage) is drastic.
`0020 For a particular packet stream, determining
`whether to transmit a certain packet with a full header or
`with a compressed header can be entirely dependent upon
`the compressor. However, in general, when context is to be
`initially formed for a particular packet Stream, one or more
`full header packets should be transmitted. AS compressed
`header packets are transmitted thereafter, upon the lapse of
`a certain time period, one or more full header packets are
`transmitted intermittently such that the context of the
`decompressor is maintained in Synchronization with the
`context of the compressor.
`0021
`FIG. 4 depicts an example of how full header
`packets and compressed header packets are transmitted
`when using a header compression technique. When the
`compressor of the PDCP in the transmitter receives an IP
`packet from an upper layer, the corresponding packet is
`transmitted to the receiver as a full header packet or a
`compressed header packet according to the pattern of the
`header. If it is determined that there is a need to form a new
`context or a need to update the context, the compressor
`transmits the packet as a full header packet. If it is deter
`mined that the context with respect to the header pattern of
`the corresponding packet is already formed in the decom
`preSSor, then the compressor transmits the packet as a
`compressed header packet.
`0022. The decompressor of PDCP in the receiver forms a
`context by first receiving a full header packet for a certain
`packet Stream. This is because the context will be the basis
`from which the compressed headers to be received will be
`decompressed. If the decompressor receives compressed
`header packets in a State where the context has not been
`formed, the decompressor cannot decompress the original
`header of the corresponding packet and thus will discard that
`received packet.
`0023. As such, when a header compression technique is
`used in a radio interface for a certain PS Service, the PDCP
`in the transmitter transmits the IP packets that were received
`from an upper layer in a Single Stream having the Same QoS,
`in either a "packet for forming or updating context format
`or a "a packet for not forming or updating context' format.
`However, if a "packet for forming or updating context' is
`not Successfully transmitted to the receiver, all Subsequently
`transmitted “packets for forming or updating context' can
`not be decompressed at the receiver and are thus discarded.
`Thus, a "packet for forming or updating context' is rela
`tively much more important (i.e., has higher priority) than a
`"packet for not forming or updating context'.
`0024 However, in the related art, all the data transmitted
`via a single RB has the same QoS, and relatively more
`
`important data cannot be transmitted with a higher QoS
`when compared to relatively less important data. Thus, there
`is a need for allowing data to be transmitted with different
`QoS according to its importance (i.e., priority), even though
`the data is transmitted via a Single RB.
`0025 Thus, the inventors of the present invention recog
`nized Such drawbacks of the related art and provided a
`Solution by providing a particular protocol layer of the
`transmitting side (transmitter) that initially receives Service
`data units (SDUs) having the same priority through a single
`Stream from an upper layer, processes these SDUS to gen
`erate protocol data units (PDUs) having different priorities,
`and uses respectively different transmission methods to
`transmit the generated PDUs over a radio interface in order
`to guarantee their respectively different quality of Service
`(QoS) requirements.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`0026. The features, nature, and advantages of the present
`invention will become more apparent from the detailed
`description Set forth below when taken in conjunction with
`the drawings in which like reference characters identify
`correspondingly throughout and wherein:
`0027 FIG. 1 depicts an exemplary basic structure of a
`UMTS network.
`0028 FIG. 2 depicts a radio access interface protocol
`architecture between the terminal and UTRAN that is based
`upon the 3GPP wireless access network.
`0029 FIG. 3 depicts an example of how the QoS
`between the terminal (UE) the Node B/RNC and the MSC
`(SGSN/GGSN) can be defined.
`0030 FIG. 4 depicts an example of how full header
`packets and compressed header packets are transmitted
`when using a header compression technique.
`0031 FIG. 5 shows how the priority information is also
`transferred together when the PDCP layer transfers PDUs to
`the RLC layer.
`0032 FIG. 6 shows an example where the RLC layer
`consecutively transmits priority data two times.
`0033 FIG. 7 shows an example of a discrimination
`transmission function performed at the RLC layer.
`0034 FIG. 8 shows an exemplary method where the
`PHY layer receives from the MAC layer, data blocks having
`three types of priorities, and three levels of transmission
`power are used to transmit these data blockS.
`0035 FIG.9 depicts an exemplary method that combines
`the techniques of FIGS. 7 and 8.
`0036 FIG. 10 depicts an exemplary communications
`System according to the present invention.
`0037 FIG. 11 depicts an exemplary mobile terminal
`according to the present invention.
`
`DETAILED DESCRIPTION
`0038. The following description is based upon the pres
`ently preferred exemplary and non-limiting embodiments of
`the present invention. More particularly, various inventive
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`concepts and principles embodied in Systems and methods
`therein are discussed and described.
`0039. In order to address the related art problems, the
`present invention proposes that a particular protocol layer of
`the transmitting Side (transmitter) initially receives Service
`data units (SDUs) having the same priority through a single
`Stream from an upper layer, processes these SDUS to gen
`erate protocol data units (PDUs) having different priorities,
`and uses respectively different transmission methods to
`transmit the generated PDUs over a radio interface in order
`to guarantee their respectively different quality of Service
`(QoS) requirements.
`0040 Additionally, the present invention proposes a
`method by which the priority information of each PDU is
`also transferred when each of the radio protocol layers
`transfers the PDUs having different priorities to its lower
`layers.
`0041. The present invention provides a method of pro
`cessing data packets for a radio communications System
`employing a protocol Stack with protocol layers therein, the
`method comprising: receiving data packets from an upper
`layer, each data packet having priority information related
`thereto generated by and Sent from the upper layer, proceSS
`ing the received data packets by using the priority informa
`tion; and transferring the processed data packets to a first
`lower layer according to the priority information.
`0.042
`Preferably, the data packets can be received in
`Service data units and transferred in protocol data units.
`Also, the receiving, processing and transferring procedures
`can be performed by a RLC layer.
`0.043
`Here, the upper layer can be a PDCP layer, and the
`PDCP layer can receive SDUs, can perform header com
`pression thereto to generate PDUs, and can transfer each
`generated PDU together with its priority information.
`0044) The priority information can indicate whether the
`corresponding data packet includes a full header or a com
`pressed header. For example, a data packet including a full
`header has higher priority than a data packet including a
`compressed header.
`0045 Preferably, the first lower layer can be a MAC
`layer.
`0046) Also, the transferring can be performed by trans
`mitting the data packets repetitively and randomly according
`to their priorities, or by transmitting the data packets using
`respectively different radio channels according to their pri
`orities, or by transmitting the data packets using respectively
`different radio transmission techniques for a single radio
`channel according to their priorities.
`0047. Here, the transferring can be performed via respec
`tively different logical channels. Such that each logical chan
`nel is used to transfer data packets of a certain priority. Also,
`a total number logical channels can equal a total number of
`different priorities.
`0.048. The above method can further comprise the steps
`of receiving the processed data packets having different
`priorities by the first lower layer via at least one data flow;
`and transferring the received data packets to a Second lower
`layer according to their respective priorities via respectively
`different logical channels.
`
`0049. Here, a total number of data flows received from
`the first lower layer can equal a total number of different
`priorities. Also, the second lower layer can be a PHY layer.
`0050. The above method can further comprise the steps
`of receiving the data packets from the Second lower layer
`via at least one data flow; and transmitting the received data
`packets to a receiver by using different transmission power
`levels corresponding to the priorities.
`0051
`Preferably, data packets of relatively higher prior
`ity can be transmitted by using a relatively higher transmis
`Sion power. Also, the Steps can be performed in order to
`guarantee respectively different qualities of Service require
`ments. Additionally, the receiver can be a mobile Station, a
`user equipment, or other communications terminal.
`0052 Hereafter, each particular method will be explained
`for an exemplary situation where Internet Protocol (IP)
`packets are transmitted over a radio interface after header
`compression is performed thereto.
`0.053
`First, the PDCP layer receives IP packets (namely,
`SDUS) through a single stream from an upper layer and
`performs header compression thereto to generate PDUS that
`include full headers or compressed headers. Then, the PDCP
`layer transfers the generated PDUs to the RLC layer together
`with information indicating the priority for each PDU. Here,
`Such priority information can be expressed in a variety of
`ways. For example, whether the packet includes a full
`header or a compressed header may be informed, or the
`priorities may be divided into many levels (degrees) Such
`that packets including full headers are regarded as high
`priority and packets including compressed headers are
`regarded as low priority, or various other expressions (e.g.,
`degrees of priority or importance) may be used.
`0054 FIG. 5 shows how the priority information is also
`transferred together when the PDCP layer transfers PDUs to
`the RLC layer. Although the transferring of PDUs together
`with their priorities from the PDCP layer to the RLC layer
`is shown, other radio protocol layers may transfer PDUs
`together with their priority information to its lower layer.
`0055. There can be many transmitting methods used for
`a radio protocol layer to guarantee respectively different
`QoS according to the priority of data. The present invention
`presents a few exemplary methods merely for the Sake of
`explanation, but it can be easily understood that other
`methods can be used as well.
`0056 (1) Method for Repetitive Transmission of Priority
`Data.
`0057 This method relates to randomly transmitting high
`priority data (i.e., important data) repetitively several times
`performed by a particular radio protocol layer. The repetitive
`transmission may be based upon feedback information from
`the receiving Side (receiver) or without Such feedback infor
`mation. Also, for repetitive transmissions without feedback
`from the receiving Side, the data with high priority may be
`consecutively transmitted repeatedly, or after initially trans
`mitting once, the high priority data may be Selectively
`transmitted repeatedly during a Selected duration when no
`other data needs to be transmitted or a Small amount of other
`data needs to be transmitted. For either method, the radio
`protocol layer requires a function of Storing the important
`(priority) data to allow repetitive transmission thereof.
`
`Ex.1010 / Page 15 of 19Ex.1010 / Page 15 of 19
`
`TESLA, INC.TESLA, INC.
`
`

`

`US 2005/0238051A1
`
`Oct. 27, 2005
`
`0.058 FIG. 6 shows an example where the RLC layer
`consecutively transmits priority data two times. Although
`not shown in FIG. 6, if there are three or more types of
`priorities, the number of repetitive transmissions can be Set
`differently according to the priorities. Also, although the
`repetitive transmission of priority data is exemplary shown
`for an RLC layer, Such repetitive transmissions can also be
`performed by other types of radio protocol layers.
`0059 (2) Method of Transmitting Data Using Respec
`tively Different Radio Channels According to Priority.
`0060. In this method, a plurality of radio channels are
`established for one radio bearer (RB) according to the
`number of priority data types, and the data are transmitted
`through respectively different radio channels according to
`their priority. To achieve this, a function for a particular layer
`of the radio protocol to discriminate according to priority,
`the data received through a single Stream from an upper
`layer and to transmit Such data Via different channels is
`neceSSary.
`0061
`FIG. 7 shows an example of a discrimination
`transmission function performed at the RLC layer. AS
`shown, the RLC layer receives from an upper layer, SDUs
`having three different kinds of priorities, and transferS these
`SDUs to a MAC layer according to their priorities through
`respectively different logical channels. Then, the MAC layer
`and the PHY layer use the transport channel and physical
`channel respectively connected to each logical channel to
`transmit the data of different priorities through respectively
`different channels. Here, the MAC layer and t