KR200390067Y1 - Wireless communication system for minimizing redundant enhanced uplink allocation requests and fault-isolating enhanced uplink transmission failures - Google Patents

Abstract

The present invention relates to an apparatus for minimizing redundant enhanced uplink (EU) allocation requests and fault-isolated EU transmission failures occurring between a wireless transmit / receive unit (WTRU) and a Node-B. The WTRU sends an enhanced dedicated channel (E-DCH) allocation request to the Node-B via an uplink (UL) EU channel. In one embodiment, if the E-DCH assignment cannot be provided within a predetermined time, the Node-B sends an acknowledgment message to the WTRU over a downlink (DL) EU signaling channel, without transmission of the E-DCH assignment information. The request is queued to Node-B, and the WTRU refrains from sending the same request until time expires or resources become available. In another embodiment, the EU is determined by determining whether the E-DCH allocation request was not successfully transmitted over the UL EL channel or whether the channel allocation information was not successfully transmitted over the DL EU signaling channel. Appropriate actions are taken to correct the transmission failures.

Description

WIRELESS COMMUNICATION SYSTEM FOR MINIMIZING REDUNDANT ENHANCED UPLINK ALLOCATION REQUESTS AND FAULT-ISOLATING ENHANCED UPLINK TRANSMISSION FAILURES}

The present invention relates to a wireless communication system including a wireless transmit / receive unit (WTRU), one or more Node-Bs, and a radio network controller (RNC). More specifically, the present invention relates to an apparatus for minimizing redundant enhanced uplink (EU) allocation requests and fault-isolated EU transmission failures.

Methods for improving uplink (UL) coverage, throughput, and transmission delay are being investigated in Release 6 (R6) of the 3rd Generation Partnership Project (3GPP). In order to successfully implement these methods, scheduling and allocation of UL radio resources has been moved from the RNC to Node-B, so that Node-B, even if the RNC retains overall control over Node-B, In the short term, UL radio resources can be determined and managed more efficiently than RNC.

In order for the WTRU to transmit on an enhanced dedicated channel (E-DCH), the WTRU must identify the need for E-DCH transmission by sending E-DCH channel assignment requests to the Node-B. Next, the Node-B provides the WTRU that has requested the E-DCH channel for allocation of the physical resources of the E-DCH.

If there are not enough UL resources for E-DCH channel allocation requests, Node-B may not immediately allocate resources of the E-DCH transmission for all the WTRUs that have requested the E-DCH. If the WTRU does not receive the E-DCH assignment within a predetermined time, the WTRU may resend the request until the WTRU receives the E-DCH channel assignment information.

Since the transmission of the E-DCH channel allocation request interferes with other WTRUs, the UL EL will increase the UL interference if each WTRU transmits and retransmits the same channel allocation request several times. Thus, the overall efficiency of the system will be degraded.

Thus, there is a need to minimize the use of UL signaling channels while maintaining proper EU scheduling operation. There is also a need for a procedure for fault-isolated EU transmission failures.

The present invention is directed to a method and apparatus for minimizing redundant EU allocation requests and fault-isolated EU transmission failures occurring between a WTRU and a Node-B. When the WTRU has scheduled to send E-DCH data, the WTRU sends an E-DCH allocation request to Node-B over a UL EU channel.

In one embodiment, Node-B receives the channel assignment request and determines whether channel assignment can be provided for the WTRU within a given channel request response time. If the channel allocation for the WTRU can be provided within a given channel request response time, the Node-B sends scheduling information (ie, E-DCH channel allocation information) to the WTRU. Otherwise, Node-B sends only an acknowledgment message to the WTRU indicating that the channel assignment request has been received, without transmission of channel assignment. In response to the confirmation message, the WTRU refrains from sending the same channel assignment request for a predetermined maximum time for assignment and the request is queued to Node-B. If the maximum allocation time expires without receiving a channel assignment, the WTRU resends the channel assignment request.

In another embodiment, the EU is determined by determining whether the E-DCH allocation request was not successfully transmitted over the UL EL channel or whether the channel allocation information was not successfully transmitted over the DL EU signaling channel. Appropriate actions are taken to correct the transmission failures.

The invention can be understood in more detail from the following description of the preferred embodiment, which has been presented by way of example and is to be understood in connection with the accompanying drawings.

In the following, the term "WTRU" includes, but is not limited to, a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a pager, or any other type of device capable of operating in a wireless environment. The term "node-B", referred to below, includes, but is not limited to, a base station, a site controller, an access point, or any other type of interfacing device in a wireless environment.

Specifications of the present invention may be integrated into an integrated circuit (IC) or may consist of a circuit having a plurality of interconnecting components.

1 is a block diagram of a wireless communication system 100 according to the present invention. System 100 includes WTRU 102, one or more Node-Bs 104, and RNC 106. The RNC 106 controls overall EU operation by configuring EU parameters for the Node-B 104 and the WTRU 102, such as the maximum allowed EU transmit power per Node-B or the available channel resources. do. The WTRU 102 sends a channel assignment request to the Node-B 104 over the UL EU channel 110 and the Node-B 104 channels over one or more downlink (DL) EU signaling channels 112. Send allocation information. After EU radio resources are allocated for the WTRU 102, the WTRU 102 transmits data over the UL EU channel 110. Node-B 104 includes a request priority queue 114 for queuing E-DCH allocation requests and a maximum allocation time timer 116 for establishing an E-DCH allocation request response time. The WTRU 102 includes a channel assignment response timer 118 for generating periodic channel assignment requests when no channel assignment has been received from the Node-B 104.

2 is a flow diagram of a process 200 for reducing congestion in a UL EU channel 110 in accordance with an embodiment of the present invention. If the WTRU 102 has E-DCH data to transmit, the WTRU 102 sends an E-DCH allocation request to the Node-B 104 over the UL EU channel 110 (step 202). The signaling of the E-DCH allocation request may be signaling of a physical or medium access control (MAC) layer.

Upon receiving the E-DCH allocation request from the WTRU 102, the Node-B 104 determines whether there are resources available for E-DCH allocation to the WTRU within a predetermined channel request response time (step 204). The channel request response time is the maximum time that Node-B 104 must respond to a channel assignment request within that time. The channel request response time established by Node-B 104's maximum allocation time timer 116 is activated by Node-B 104 when an E-DCH allocation request is received. The channel request response time may be a fixed value of the system or may be configured for each EU radio access bearer (RAB) by the RNC 106 and signaled to both the Node-B 104 and the WTRU 102.

If the E-DCH resources are available, the Node-B 104 sends an acknowledgment message indicating that the E-DCH allocation request has been received, within the channel request response time, over the DL EU signaling channel 112. (Step 206), and scheduling information (i.e., E-DCH allocation information) is also transmitted (step 207). The WTRU 102 then transmits data on the UL EU channel 110 in accordance with the scheduling information (step 208).

If the E-DCH resources cannot be allocated before the channel request response time expires, the Node-B 104 sends an acknowledgment message to the WTRU 102 indicating that the E-DCH allocation request has been received, but the channel request. No scheduling information is sent to the WTRU 102 before the response time expires (step 210). The acknowledgment message does not include scheduling information, only acknowledgment that Node-B 104 has received the channel assignment request and will process the request when resources are available.

According to an embodiment of the present invention, the E-DCH allocation request indicates a priority. After sending an acknowledgment message to the WTRU 102 confirming receipt of the E-DCH assignment request, the E-DCH assignment request is based on the request priority queue 114 of the Node-B 104 based on the indicated priority of the request. (Step 212). When the request is placed in the response priority queue 114, the maximum allocation time timer 116 is activated, or equivalently, the reception time of the E-DCH allocation request is recorded. The maximum allocation time is the maximum time that the E-DCH allocation request should be served within that time before finally determining that the E-DCH allocation request has failed. The maximum allocation time may be unique for each transmission that maps to a given data flow or data priority class.

Requests in the request priority queue 114 of the Node-B 104 may be serviced in a first in, first out (FIFO) manner. If there are not enough resources, the allocation is further delayed until it becomes available. If sufficient resources exist, Node-B 104 services one or more requests of request priority queue 114.

If a confirmation message is received from the Node-B 104 in response to receiving the E-DCH allocation request, the WTRU 102 determines whether scheduling information has also been received or whether only the receipt of the channel allocation request has been confirmed. Check If scheduling information has been received, the WTRU 102 sends data over the UL EU channel 110 in accordance with the scheduling information specified by the Node-B 104 (step 208). If only acknowledgment of receipt of the E-DCH assignment request has been received, the WTRU 102 recognizes that Node-B 104 has received the E-DCH assignment request and refrains from retransmitting the same request (step 214).

After verifying that a channel assignment request has been received and that there is no scheduling information, Node-B 104 later determines that the WTRU 102's requests are queued in Node-B 104's request priority queue 114. EU channel assignments may be provided for 102. Periodically, maybe every time a transmit time interval (TTI) passes in step 216, Node-B 104 may determine whether resources may be used for allocation of requests in request priority queue 114. A determination is made (step 218). If there are resources available, process 200 proceeds to steps 207 and 208.

If no resources are available, Node-B 104 determines whether the maximum allocation time timer 116 has expired (step 220).

If the maximum allocation time timer 116 has not expired, as determined in step 220, the process 200 waits for the subsequent TTI in step 216 and the Node-B 104 sends the E-DCH allocation information to the WTRU 102. Send. Node-B 104 may prioritize allocations near the expiration of the maximum allocation time.

After the maximum allocation time timer 116 expires or, equivalently, after a predetermined time has elapsed since the recorded request reception time, the WTRU 102 tracks the maximum allocation time for each E-DCH allocation request. It relies on its channel assignment response timer 118 to do so. The WTRU 102 sets a channel assignment response timer 118 whenever the WTRU 102 sends an E-DCH allocation request to the Node-B 104 and upon expiration of the channel assignment response timer 118. Recognize allocation failure. Alternatively, if the WTRU 102 does not have its own equivalent channel assignment response timer 118, the Node-B 104 notifies the WTRU 102 of the failure of the assignment. If the WTRU 102 has its own channel assignment response timer 118, then the Node-B 104 does not need to notify the WTRU 102 of the failure.

If an E-DCH allocation failure occurs, the WTRU 102 has several options. The WTRU 102 may retransmit the E-DCH allocation request or the updated request to the Node-B 104 (step 224). Step 224 may be performed periodically whenever the channel assignment response timer 118 expires. Alternatively, if the WTRU 102 has additional E-DCH data to send, the WTRU 102 may discard the data it has requested for allocation and transmit an updated E-DCH allocation request. (Step 226).

3 is a flow diagram of a process 300 for determining a signaling channel failure during channel allocation in accordance with another embodiment of the present invention. If the WTRU 102 has EU data to send, the WTRU 102 sends an E-DCH assignment request to the Node-B 104 and activates the channel assignment response timer 118 (step 302). After transmitting the E-DCH allocation request, the WTRU 102 receives the reception of scheduling information (ie, E-DCH allocation information) from the Node-B 104 until the channel assignment response timer 118 expires. Wait If the WTRU 102 fails to receive scheduling information from the Node-B 104 before the channel assignment response timer 118 expires (step 304), the WTRU 102 requests the same E-DCH allocation request with a retransmission indicator. Or resend the updated E-DCH allocation request (step 306).

In this case, the WTRU 102 does not know whether UL EU signaling (ie, E-DCH allocation request) or DL EU signaling (ie, channel allocation) is lost. If Node-B 104 receives the re-transmitted E-DCH allocation request (step 308), Node-B 104 determines where the failure occurred (ie, the E-DCH in UL EU channel 110). Whether it is an allocation request or channel allocation via DL EU signaling channel 112). If Node-B 104 receives an unserved, retransmitted E-DCH assignment request, Node-B 104 indicates that the E-DCH assignment request was not successfully delivered over UL EU channel 110. It is determined (step 312). If Node-B 104 receives the served, retransmitted E-DCH allocation request, Node-B 104 determines that the channel allocation information was not successfully delivered over DL EU signaling channel 112. (Step 314). For any of steps 312 and 314, Node-B 104 takes appropriate corrective actions according to the determined failure. Node-B 104 then processes the received request (step 316).

While the features and elements of the present invention have been described in certain combinations of preferred embodiments, each feature or element may be used alone or with other features and elements of the present invention without the other features and elements of the preferred embodiments. It can be used in various combinations with or without.

Although the present invention has been described in terms of preferred embodiments, other variations that fall within the scope of the present invention as outlined in the following claims will be apparent to those skilled in the art.

Thus, the present invention ensures that E-DCH allocation requests have been received by Node-B 104 if the E-DCH allocation request is not provided immediately by Node-B 104, and UL EU signaling. Ensure that the load is minimized. By using the method of the present invention, more efficient use of physical UL resources is possible.

1 is a block diagram of a wireless communication system according to the present invention.

2 is a flowchart of a processor for reducing congestion in a UL EU channel established in the system of FIG. 1 in accordance with an embodiment of the present invention.

3 is a flow diagram of a process for determining signaling channel failures and taking corrective actions during channel allocation in accordance with another embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100: wireless communication system

102: WTRU

104: Node-B (s)

106: RNC

110: UL EU Channel

112: DL EU signaling channel

114: request priority queue

116: maximum allocation time timer

118: channel assignment response timer

Claims (18)

As a wireless communication system, (a) a wireless transmit / receive unit (WTRU) for transmitting an enhanced dedicated channel (E-DCH) allocation request; (b) one or more Node-Bs for receiving the E-DCH allocation request, (b1) a maximum allocation time timer; (b2) one or more Node-Bs having an allocation request priority queue; (c) a UL uplink enhanced uplink (UL EU) channel established between the WTRU and the Node-B, (Iii) the WTRU sends the E-DCH allocation request to the Node-B via the UL EU channel; (Ii) the Node-B receives the E-DCH allocation request and determines whether E-DCH allocation for the WTRU can be provided within a predetermined channel request response time established by the timer, (Iii) the Node-B sends an acknowledgment message to the WTRU indicating that the E-DCH allocation request has been received; (Iii) if the Node-B determines that E-DCH allocation for the WTRU cannot be provided before the timer expires, the Node-B stores the E-DCH allocation request in the allocation request priority queue, in which case, Wherein the WTRU refrains from retransmitting the same E-DCH allocation request on the UL EU channel during the predetermined channel request response time. The method of claim 1, The E-DCH allocation request indicates a priority of the request, and the E-DCH request is stored in the request priority queue based on the priority indicated by the E-DCH allocation request. system. The method of claim 1, The Node-B activates the timer, determines whether there are resources available for allocating the queued request, and notifies the WTRU of a resource allocation failure when the maximum allocation time timer expires. Wireless communication system. The method of claim 1, The timer records the time when the Node-B receives the E-DCH allocation request, and the Node-B determines whether there are resources available for allocating the queued request, and the node -B informs the WTRU of a resource allocation failure when a predetermined time has elapsed since the recorded time, which is determined by the timer. The method of claim 1, The WTRU has a channel assignment response timer that is activated when the E-DCH allocation request is sent to the Node-B, and the channel assignment without the Node-B transmitting E-DCH allocation information to the WTRU. If the response timer expires, the WTRU retransmits the E-DCH allocation request to the Node-B. The method of claim 5, And the channel assignment response timer is activated periodically. The method of claim 1, The WTRU has a channel assignment response timer that is activated when the E-DCH assignment request is sent to the Node-B, the WTRU discards data associated with the E-DCH assignment request, and the WTRU is updated E -Transmit a DCH allocation request to the Node-B via the UL EU channel. The method of claim 7, wherein And the channel assignment response timer is activated periodically. The method of claim 1, The Node-B determines if there are resources available for allocating the queued request, the Node-B sends E-DCH allocation information to the WTRU, and the WTRU is in the E-DCH allocation information. And transmit E-DCH data to the Node-B using the resources according to the request. (a) a maximum allocation time timer; (b) means for receiving an E-DCH allocation request; (c) an allocation request priority queue for storing the E-DCH allocation request of the allocation request; (d) means for determining whether E-DCH allocation for a wireless transmit / receive unit (WTRU) can be provided within a predetermined channel request response time defined by the timer; (e) means for transmitting a confirmation message indicating that the E-DCH allocation request has been received. The method of claim 10, The E-DCH allocation request indicates a priority of the request, and the E-DCH request is stored in the request priority queue based on the priority indicated by the E-DCH allocation request. B. The method of claim 10, The Node-B activates the timer, determines whether there are resources available for allocating the queued request, and indicates that a resource allocation failure has occurred when the maximum allocation time timer expires. Node-B, which is to send a message. The method of claim 10, The timer records the time when the Node-B receives the E-DCH allocation request, and the Node-B determines whether there are resources available for allocating the queued request, and the node Node-B transmits a message indicating that a resource allocation failure has occurred when a predetermined time has elapsed since the recorded time, which is determined by the timer. (a) a channel assignment response timer; (b) means for sending an enhanced dedicated channel (E-DCH) allocation request and activating the timer; (c) means for determining whether E-DCH scheduling information has been received in response to the request before the timer expires; (d) means for retransmitting the request or sending an updated E-DCH allocation request if the E-DCH scheduling information has not been received before the timer expires. (a) a channel assignment response timer; (b) means for sending an enhanced dedicated channel (E-DCH) allocation request and activating the timer; (c) means for determining whether E-DCH scheduling information has been received in response to the request before the timer expires; (d) means for retransmitting the request or sending an updated E-DCH allocation request if the E-DCH scheduling information was not received before the timer expired. (a) a maximum allocation time timer; (b) means for receiving an enhanced dedicated channel (E-DCH) allocation request; (c) an allocation request priority queue for storing the E-DCH allocation request of the allocation request; (d) means for determining whether E-DCH allocation for a wireless transmit / receive unit (WTRU) can be provided within a predetermined channel request response time defined by the timer; (e) means for transmitting an acknowledgment message indicating that the E-DCH allocation request has been received. A wireless communication system configured to fail-isolate enhanced uplink (EU) transmission failures, the method comprising: (a) a wireless transmit / receive unit (WTRU); (b) one or more Node-Bs; (c) an uplink (UL) EU channel established between the WTRU and the Node-B; (d) having a downlink (DL) EU signaling channel established between the Node-B and the WTRU, If a response to a transfer request on the UL EU channel is not received by the WTRU, the WTRU retransmits an enhanced dedicated channel (E-DCH) allocation request on the UL EU channel, and the Node-B transfers the transfer. If the request has already been served, it is determined that the channel allocation information transmitted by the Node-B has not been successfully delivered to the WTRU over the DL EU signaling channel, and if the E-DCH allocation request has not yet been served, the transfer And determine that the request was not successfully delivered on the UL EU channel. The method of claim 17, And the Node-B takes a corrective action based on which of the UL and DL channels have stopped receiving a response to the previous request by the WTRU.