TWI240519B - Shared channel assignment and downlink packet scheduling - Google Patents

Abstract

A method for shared channel assignment and downlink packet scheduling combines interactive traffic and background traffic to obtain a scheduling which utilizes channel resources efficiently. The method is easy to be implemented in downlink shared channels of wireless communication. The present invention is to decide interactive connections and background connections assigned by calculating the current transmission capability of each shared channel. All interactive connections are then offered to the scheduling periodically based on the transmission rate requested by every interactive connection in order to obtain required transmission rates for every interactive connection. The background connections uses bandwidths which are not utilized for transmitting data in the channel so as to efficiently utilize the channel resources.

Description

1240519

The technical field to which the invention belongs is packet 2 (knowledge k is a shared channel allocation method, and is particularly related to a scheduling method and scheduler for transmitting multiple traffic types by packet switching). Prior Art "! (: Generation (Th: rd Generation; 3G) mobile communication system uses circuit switching and packet switching technology to provide users with wireless voice and high-speed data transmission. 3G system utilization Error correction coding and bandwidth allocation

Transmission data provides a variety of different levels of service goods f (QuaUty 〇f negative

Service; Q0S). The transmission throughput, delay, and loss rate (10ss rate) required for different types of data transmission are the same. For example, the delay time that can be tolerated during data transmission will be longer than that of a voice call, which is acceptable for data transmission. The loss rate is much lower than that of voice calls (1〇_8 &lt; <-1 10-2). The table in Figure 1 shows the range of quality of service (QoS) required for transmission of wireless communication applications of different nature in general. Generally, the traffic of these non-communication applications can be divided into four types: conversation,,

(conversational), streaming, interactive, and backgrund. The conversation ^ is mainly for audio calls. The stream type is mainly used for multimedia applications. Since the data transmitted by these two types of traffic is real-time, the allowable delay time will be strictly limited, and there will be stable and continuous Data transmission, so these two applications usually transmit lean materials on specific dedicated wireless channels, that is, use circuit switching technology to transmit. on the other hand,

1240519 V. Description of the invention (2) '---- One, the transmission traffic of the communication network applications such as browsing the web or online games belongs to the parent interactive traffic, and the downloading data belongs to the background traffic. This kind of network data is transmitted using packet exchange technology. As shown in Figure 2, the packet traffic is different from voice. The data transmission is not stable and continuous. It can be divided into many within the time of a packet service connection time of 20. A packet period 201 (bursty period) to be transmitted at the same time, and an idle period p (idleperiod) 202 without packet transmission. When using the packet parent exchange technology, the downlink to the client (from the base station to the client) can be transmitted using the Physical Downlink Shared Channels (PDSCHs). Therefore, in the design, it is necessary to provide Fair and service-assured downlink packet scheduling algorithm, in accordance with the quality of service (QoS) required by various applications, provides satisfactory transmission rates to users. In previous research on the allocation of shared channels, It is to provide fairness between transmission needs, and the complexity of the design of the scheduling algorithm is quite high, which causes difficulty in implementation. For example, scheduling algorithms used on wireless Time Division Multiple Access (TDMA) networks include the channel state-dependent packet scheduling method.

State Dependent Packet Scheduling (CSDPS), Idealized Wireless Fair Queuing (IWFQ), and scheduling algorithms for code division multiple access (CDMA) networks Including packet-by-packet general processor shared scheduling method (Packet-by-Packet

1240519 V. Description of the invention (3)

Generalized Processor Sharing-Base Scheduling; Schedu ng; DRS) and so on. SUMMARY OF THE INVENTION For simple calculation, the flow rate of the inter-flow rate transmission wheel is simple and easy. The algorithm and the transmission speed of the present invention allow each volume or back to achieve the guarantee required to achieve the transmission. One purpose scheduler, the accuracy is transmitted. Another purpose of an entity's background traffic is to perform scheduling as described above, and because of the bandwidth, it is to provide an algorithm for scheduling the downlink packets of wireless communications. Li Chang: Provide a shared channel allocation and scheduling to ensure that all applications in the interactive traffic can be requested. Provide a packet scheduling algorithm and chain shared drought channel to be fully utilized to transmit data. The present invention uses the periodic method to implement interactive simplicity, and can provide transmission background traffic. It can fully utilize interactive traffic to use resources, and the transmission bandwidth is effective. The present invention provides a shared channel allocation and scheduling. (Shared annel Assignment and Scheduling; SCAS) method, schedule the first connection with =. First, find a physical downlink-sub-channel (PhySlcai Downlink Shared Channe has a strong support for the transmission rate Γι, so the first connection is assigned to the channel to transfer data to the channel, and then the connection is calculated according to the transmission rate r 丨TiDle Period '. According to the time period

1240519 Fifth invention description (4) ^ Second, the middle time of PDSCH allocation (time is the starting time, Λ Λ # 丄 丄 0 τ ^, 'the time of the first connection is assigned 仏 dt time start' | interval In the time period τ〗, the first connection is: cross: = line use: meaning. In the embodiment of the present invention, the #_next page of the page capable of supporting the transmission rate r cannot be found and the first connection is transmitted. an :: shared channel 'then block coffin rate 0 entity down-chain sharing = temple stop until a second connection can be scheduled that can support the pass to redemit the first rate, the shared channel remains; :::: ;;; = The channel 'If the entity is off-chain I &quot; 2 calculates the time of the second connection', Ί2 and compares according to the transmission rate, it will compare the daytime interval I and the time period τ to the yttrium f ± ° 2 and will correspond to The scheduling method of the flail apricots and sweet potatoes for a small period of time is also from the private person to be assigned. The connections of the eight connections of the eighth school are transmitted at intervals of 2㈣I. Corresponding to the second connection in the embodiment is: ; Formula = data that can be transmitted. After the present invention is scheduled with the second connection, the third connection is engraved with the-connection, or When there is no data to be transmitted, but the data is not allocated in the shared channel, in the embodiment of the present invention, the third connection is 1 = the second connection. In the case of the dental office, the type connection, such as downloading the building, the present invention also provides a distribution jt The ancient, 2, and several PDSCHs that have been assigned to PDSCH including many moments are scheduled on the Doosan Road 11 '$ with a split connection to arrange spears. ^ Of the present invention. Parent interactive connection and several Background buffer, a background-type traffic buffer number includes several interactive traffic balancers, and a scheduling unit. Each

〇213-A40054, nfF (Nl); K9227; KAREN.ptd 1240519

Parent interflow buffer. Background streaming data. The schedule corresponds to a time. Firstly, one unit is retrieved, and the time corresponding to the interval is obtained. The data is entered for an interactive continuous input. The volume buffers of the present invention are buffers that store corresponding data to be transmitted by an interactive connection, and buffers that store all the elements to be transmitted by the background connection. Transmissions requested by each interactive connection The rate calculates the period and sequentially from each interactive traffic buffer, the time data is 'scheduled into the PDSCH, and the next order will be taken from the interactive traffic buffer' into the PDSCH every cycle. And from the time when the background-type traffic buffer is not assigned to any interactive connection, or it has been divided into 1 wiring, but this interactive connection has no data at this time for transmitting these interactive traffic buffers and background in the embodiment. First In First Out (FIFO) buffering In order to make the above and other objects, features, and advantages of the present invention more comprehensible, a preferred embodiment is given below, in conjunction with the accompanying drawings, The details are as follows. Implementation mode The Wideband Code Division Multiple Access (WCDMA) specification in the Universal Mobile Telecommunication System (UMTS) proposed by the 3rd Generation Partnership Project (3GPP) uses the Orthogonal Variable Spreading Factor (0VSF) codes can support a transmission rate of up to 2Mbps. In a CDMA system, this OVSF code can provide different transmission rates to the user, that is, the 0 VSF code assigned to the user.

1240519 V. Description of the invention (6) Different spreading factors (SF) can provide different transmission rates. As shown in the 0VSF code tree in Figure 3, for example, if the ideal transmission speed of layer 0 (SF = 1), that is, the uppermost layer is 60 Kbps, layer 1 (SF = 2), and layer 2 The ideal transmission speed (SF = 4) is 30Kbps and 15Kbps, respectively. Therefore, when the channel is allocated, the codes of different layers can be allocated according to the desired transmission rate of each connection. As shown in FIG. 4, the scheduler of the present invention includes a plurality of interactive flow buffers 40b, 40n, a background flow buffer 42, and a scheduling unit 44. The scheduling unit fetches data from these buffers in a specific order and transmits the data using PDSCH 46 coded with 0VSF code Ck, m. The interactive flow buffers 4 0 1 to 4 0 η and the background flow buffer 4 2 are buffers of First In First Out (FIFO). Suppose that pDSCH transmits a set of n interactive connections (Qr ~ Qn) s, that is, S = {Qi, Q2, ..., Qn}, and each interactive traffic buffer 401 ~ 4n stores the corresponding An interactive connection (Q ^ Qn), these interactive connections can be used to browse websites or applications such as online games. All the background connections B are stored in the back-type flow buffer 42, and the background connections can be used for downloading files and the like. 7. The PDSCH transmission rate in the embodiment of the present invention is Rk. This speed is determined by its 0VSF code Ck, mK. Equation (1) shows the formula for calculating the transmission rate. In equation (3), r is a specific rate specified by 3GPP, ^ is about 7 · 5 ~ 8 Kbit / s, and K is the number of layers of the 0VSF code tree (by 0, 1, 0, ...) Κ; in the WCDMA downlink, κ = 9).

Rk = 2K ~ kr Equation (1) The interactive transmission rate in the UMTS system. The requested transmission rate r can be determined by

1240519 V. Description of the invention (7) Equation (2) is expressed. Equation (2) Towards, a new interactive connection with a transmission rate of Γη% is required to transfer data on PDSCH 46. It is necessary to verify the transmission capability of PDSCH 46 to support this transmission. Rate r &quot;. That is, equation (3) = the pieces can be conformed to 'equation (3) will support the transmission of mcH 46 for all interactive connections S that have been transmitted in the PDSCH 46, please untransmit the rate, and then contact the new &Amp; Compare Requested Transmission Rates.

&gt; K

V Equation (3) is connected to the tft parent interactive connection Qn conforms to Equation (3), which indicates that this PDSCH 46 can still be two or four feet wide, and the speed 'so this interactive connection is assigned ΐ: to listen to the transmission This set of interactive connections $ will continue to look for if any PDSCH can support this transmission rate Γη if the request transfer of ^ interconnect_n is larger than the remaining transmission rate ', otherwise this Interactive connection Qn ^^ 求 会 ί: 5: and 7 T explicitly ask for 'until there is a PDSCH with sufficient bandwidth to reach the transmission rate of this interactive connection r, please east. ~

0213-A40054TW (Nl); K9227; KAREN.ptd $ 12 pages 1240519 V. Description of the invention (8) Next, when scheduling 54 4- ^ ^ spear ^, first calculate on PDSCH 46 # 沾 bis The transmission duration of γ (the duration of all duratioiODi transported by the heart, and the duration of the transmission connected to the time cycle type / ^ period) '. Each of these interactions is set to the PDSCH's pass-through, Γ '&quot;, and the duration of the transfer wheel phase phase TTI represents an interval (m) D on the channel, that is, D "_D, here $ ハ 丨The duration of the time period. The time between two consecutive transfers in the connection &amp; &gt; 2 connection, such as equation ⑷ ::, parent, the time period τ 丨 for the interconnection connection is transmitted by the request Rate factory instead:

7 \: D

, 7; J Nettle (4) Example, in Figure 5 is straightforward. The invented SCAS method was used at -PDSC ... to ask the transmission rate of the channel, and the horizontal axis is shown in this figure. You can see the channel. The resource 50 is cut into various long-term productions.), Suppose that at this time, 2 ^ = is a quarter of the _ transmission speed, and is ^^ twice. Therefore, the time period T1 of Ql is 4D, and I The time data: m; i The order of the invention in arranging the interactive connection transmission is based on the size of the time interval Ti, and the connection with the smallest time period Ti will be arranged to be transmitted first, for example, in the example in Figure 5 In Q1, the time period Q of Q1 is smaller than the time period (8D) of Q and 2, so Qi will be ranked at the first time and communicated at first, and the time period of Qi at the first time and every subsequent time Ί , Such as t, \, 5 9

〇213.A40〇54TWF (Nl); K9227; KAREN.ptd Page 13 1240519 V. Description of the invention (9) tl3, tn, first-class time are all arranged to send data to &amp; Q2, and every interval Q2 time period τ2 after the second time t2, such as time tio, tls, etc., are arranged to send data to Q2. If the time periods of multiple connections are the same at the same time, the order of the rounds of these connections of the same period can be arbitrarily arranged. The SC AS method of the present invention further includes arranging the background connection for transmission in two types of PDSCH resources 50. One is the time when it is not assigned to any interactive connection, as shown in FIG. 5, t4, t6, t? , T8, tn, ti2, tu, U, t16, t19, t2. , And the time at t22, the other is the time originally allocated to the interactive connection Qi, but Qi is idle at that time (that is, no data transmission). For example, the time at t 9 in the figure is allocated to A, but No data needs to be transmitted at that time. Figure 5 shows the darker shaded moment 5 2 is Q! There is data transmitted on the PDSCH, and the lighter shaded moment 54 is Q2 with data transmitted on the PDSCH. The transmission rate requirements of the present invention and the background mode are 'redistributed and periodically interconnected to reach each other's way. The transmission of hundreds of interactions does not strictly have all the space-time and drought-prone traffic.' Desired connection rate (that is, to limit the immediate transmission and allocation and scheduling characteristics, because the transaction will first calculate the rate that can support the requested parent interactive connection. The transmission rate must always be equal to Rk); The delay time or transmission, combined with the SC AS method, combined with the interactive inter-flow usually has a PDSCH that transmits the current transmission rate of each PDSCH. The data is transmitted to ensure that each communication is in accordance with The application of Equation (3) can achieve the allocation of channel background traffic. For the application of round-robin rate, the unused frequency can be transmitted in PDSCH.

1240519 V. Description of the invention (10) Wide to achieve efficient use of channel resources. Although the present invention has been disclosed in the preferred embodiment as above, it is not intended to limit the present invention. Any person skilled in the art can make some modifications and retouching without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection shall be determined by the scope of the attached patent application.

0213A40054TWF (N1); K9227; KAREN. A typical traffic state; an example of a code tree; a simplified diagram of; distribution and scheduling (SCAS); FIG. 3 shows an orthogonal variable expansion factor (0VSF); FIG. 4 is a scheduler according to an embodiment of the present invention; FIG. 5 shows an example of an implementation of the shared channel division method according to the present invention. Symbol description B ~ background connection request; D ~ transmission time interval of time (τ T I);

Ql ~ Qn ~ Parent interactive connection request; Ding, T'2 ~ Time period of parent interactive connection; t ~ t22 ~ PDSCH time; 2 0 ~ packet service connection time; 4 2 ~ background Traffic buffer; 44 ~ scheduling unit; 46 ~ physical downlink shared channel (PDSCH); 50 ~ physical downlink shared channel (PDSCH) resources; 5 2 ~ data with A connection is transmitted; 54 ~% connection The data of the line is transmitted; 201 ~ packet burst period (bursty peri〇d); 20 2 ~ packet idle period (idle peri〇d);

1240519 Schematic description 401 ~ 40η ~ Interactive traffic buffer. _Circle Page 17 0213 -A40054TWF (N1); K9227; KAREN.p t d

Claims (1)

1240519 VI. Scope of patent application 1. A shared channel assignment and scheduling (SCAS) method, in which a first connection schedule for a transmission rate q is included, including the following steps: The physical downlink 1 ink shared channels (PDSCHs) are still capable of supporting the transmission rate to allocate the first connection to the physical downlink shared channel; 1 determine the first connection according to the transmission rate ri Time period of the line)! ^; And ⑤ ”(tune according to the size of the time period t, allocate a time slot of the entity's off-chain share, 甬 ,, and multiple times (time slot) to the beginning of the first connection Data transmission is started from time to time, and from the start time, the time of the interval between the interstitial periods is allocated to the first connection. W 4 2 · The method of allocating and sharing shared channels as described in item 丨 of the scope of patent application Wherein, the first connection is an interactive connection. Wang 3. The method for allocating and arranging shared channels as described in item 丨 of the patent application scope, wherein the request transmission speed of the first connection is It is limited by two: 1 A qe {0, l, 2U} Formula r is a specific rate specified by the specification, and κ is the Orthogonal Variable Spreading Fact〇r. OVSF code The number of layers of the tree. ' ^ 40519 The method of applying for a patent scope, I: ΐ The allocation and scheduling of the shared channel described in item 1 in the third connection schedule in this third connection schedule, including the following steps: Allocation of allocation time. In the chain sharing channel, no data is transmitted when the flute-Γ connection is transmitted; and when the connection is transmitted at the time of transmission, the data originally allocated to the -th-Biedering 5th connection is used. Method: The 6 111 connection of the shared channel assignment and scheduling is a background connection. The method is more like :: ;; ::::-connection transmission request and so on. A physical downlink shared communication that has a transmission rate ^!--: Ϊ́ ® &quot; &quot; κ # # &quot; Time interval (Transmission; the two channels have fixed transmission at each time, the calculation method is according to this; e 2. m) D, the time wheel rate Rk and the -th connection require the dry channel to provide-upload the transmission time interval D, that is Ti = d (r / wide speed. A ratio of the rate Γ1, then multiply by 8 · The method of claiming the first item in the patent scope, including the method of requesting wheel speed ', is: The allocation and scheduling of a dry road includes the following steps: · A second connection schedule of Γ2, If the entity's offline sharing channel is still capable of assigning the second connection to the entity's offline sharing preamble, k transmission rate I * 2, 0213-A40054TWF (Nl); K9227; KAREN.ptd Page 19 1240519 Six applications The scope of the patent and the time period τ of the second connection is determined according to the transmission rate r2. The connection between the time period eight and the time period τ = period is scheduled first, among which the connection is scheduled for ^ hours; At the beginning of the time, each interval corresponds to the time of these connections: Method 9: ϊ 2 Γΐ 围 The sharing described in No. 8 The first connection and the second connection of the eighth middle side of the channel allocation and scheduling are an interactive method. 10 As described in the patent-profit scope No. 8, the shared channel allocation The connection request transmission rate r and # ώ are limited by the following formula (i is "cut: hands ~ and bu are by 7; 2 2 V qe {0, 1, 2, U} The r in the formula is specified by the specification A specific rate, and κ is the number of layers of the positive spreading factor (0VSF) code tree. Another number 11 · The method of allocating and scheduling shared channels as described in the patent application scope No. 8, including if the entity is off-chain The shared channel cannot support the transmission rate h 'continue to find if there is a physical channel that can support the second connection, if it finds it, block and make the transmission request of the second connection wait until it finds that it can support the transmission rate _ entity down-key shared channel for r2. 1 2 · The method for allocating and scheduling shared drought channels as described in claim 8 of the patent scope, where the entity's down-chain shared channel has a fixed transmission time at each time 1240519 Declared the patent interval interval (TransmissioI1 Time Interval; TTI) D, the time periods T! And 2 are calculated according to a transmission rate Rk provided by the entity's downlink shared channel, respectively with the first The ratio of the transmission rate q to the heart required by the connection and the second connection is multiplied by the transmission time interval 〇, that is, Ti = D (Rk / ri), T2 = D (Rk / r2) 〇 1 3 · The method for assigning and scheduling shared channels as described in the scope of the patent application No. 8 further includes scheduling a third connection, including the following steps: _ After the first connection and the second connection are scheduled, Allocating unassigned moments in the entity's off-chain shared channel to the third connection to transmit data; and when no data is transmitted on the first connection or the second connection, using the originally allocated to the first connection or the The data of the third connection is transmitted at the time of the second connection. 14 The method for allocating and scheduling shared channels as described in Patent Application Scope 13, wherein the third connection is a background connection. 1 5 · — A scheduler for allocating shared channels. The scheduler is several interactive connections and several backgrounds that are assigned to a physical downlink shared channel (PDSCH). The ti me s 10 ot distribution schedule is connected, and the scheduler includes: several + interactive flow buffers, each interactive flow buffer stores the corresponding data to be transmitted by an interactive connection, and transmits The unit time of the data is the same as the transmission time interval (Transmission Time Interval; TTI) D of the moment in the entity's downlink shared channel. Two background traffic buffers store all the background connections Material, in which the unit time of transmitting data is also shared with the entity's off-chain 1240519 VI. Scope of patent application Channel-China to: Chuan ::? The interval D is the same-time period τ, ', and the transfer rate r in order 乂 2Ά ,, is calculated as a unit of time data, and is placed in the physical buffer. The time period T is shared in the channel, and then the next unit of time is taken from the resource buffer of the second type of flow buffer and is taken from the background flow buffer; the moment when the channel is interconnected or allocated However, the helmet information is provided ^ * Rate any time. As described in the scope of patent application No. 15, the moment of loss. The transmission time interval of each time of the shared channel :: solid; the calculation method of time period 1 of the entity is based on the secret of the entity 1 port 1 and the corresponding transmission rate Rk and the corresponding interactive connection are to be provided. -Ratio, then multiply it by the transmission time interval D, that is, Ti = D (R, J, J, rate factory, I, 7 · Scheduler as described in the scope of patent application No. 丨 5, ^ 1 mutual streaming buffer The device and the background-type traffic buffer are first-in-first-out (FIFO) buffers. (Hrst