HK1118163A - Method and apparatus for minimizing redundant enhanced uplink allocation requests and fault-isolating enhanced uplink transmission failures - Google Patents

Description

Method and apparatus for minimizing redundant enhanced uplink configuration requests and error isolation enhanced uplink transmission failures

Technical Field

The present invention relates to a wireless communication system, which includes a wireless transmit/receive unit (WTRU), at least one node-B and a Radio Network Controller (RNC). More particularly, the present invention relates to a method and apparatus for minimizing redundant Enhanced Uplink (EU) configuration requests and error isolation EU transmission failures.

Background

Methods for improving uplink coverage, throughput, and transmission delay time are currently being investigated in the third generation partnership project (3GPP) release 6 (R6). To successfully perform these methods, scheduling and allocation of UL radio resources is moved from a Radio Network Controller (RNC) to a node B, so that the node B can determine and manage UL radio resources on a short-range basis more efficiently than the RNC, even though the RNC maintains overall control over the node B.

In order for the WTRU to transmit on an enhanced dedicated channel (E-DCH), the WTRU must identify the need for an E-DCH transmission by transmitting an E-DCH channel configuration request to the node-B. The node B then provides the configuration of E-DCH physical resources to the WTRU that has requested the E-DCH channel.

The node-B may not immediately configure resources for E-DCH transmissions to all WTRUs that have requested the E-DCH when UL resources are not available for the E-DCH channel configuration request, and the WTRU may resend the request if the WTRU fails to receive an E-DCH configuration within a predetermined time period until the WTRU receives the E-DCH channel configuration information.

Since the transmission of the E-DCH channel configuration request interferes with other WTRUs, the UL EU channel will increase UL interference when each WTRU transmits and retransmits the same channel configuration request multiple times, and the overall efficiency of the system will decrease.

Therefore, there is a need to minimize the utilization of the UL signaling channels while maintaining proper EU scheduling. In addition, a step of error isolation of EU transmission failures is also required.

Disclosure of Invention

The present invention relates to wireless communications apparatus for minimizing redundant EU configuration requests and fault isolation EU transmission failures occurring between a WTRU and a node-B. When the WTRU has scheduled to transmit E-DCH data, the WTRU transmits an enhanced dedicated channel (E-DCH) configuration request to the node-B over an UL EU channel.

In one embodiment according to the present invention, the node-B receives the channel configuration request and determines whether channel configuration can be provided to the WTRU during a predetermined channel request response period. If the WTRU channel configuration is available within a predetermined channel request response period, the node-B sends scheduling information (i.e., E-DCH channel configuration information) to the WTRU, otherwise the node-B sends only a confirmation message to the WTRU indicating that the channel configuration request has been received but a channel configuration has not been sent. In response to the confirmation message, the WTRU refrains from transmitting the same channel configuration request for a predetermined maximum time for a configuration period and places the request in the queue of the node-B. The WTRU retransmits the channel configuration request if a channel configuration is not received for more than the maximum time to configure the period.

In another embodiment according to the present invention, appropriate measures are taken to correct EU transmission failure by determining whether an E-DCH configuration request was not successfully delivered via the UL EU channels or whether channel configuration information was not successfully delivered via the DL EU signaling channels.

Drawings

The invention may be understood in more detail by reference to the following description of a preferred embodiment, given as an example, and the accompanying drawings, in which:

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

fig. 2 is a flow chart for reducing congestion in the UL EU channel established in the system of fig. 1, in accordance with an embodiment of the present invention; and

fig. 3 is a flowchart of a procedure for determining a channel on which a signal is transmitted during a channel allocation period and performing a calibration operation according to another embodiment of the present invention.

Detailed Description

The term "WTRU" as used herein 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. When referred to hereafter, the terminology "node B" includes but is not limited to a base station, a site controller, an access point, or any other interfacing device in a wireless environment.

The features of the present invention may be integrated into an Integrated Circuit (IC) or may be configured on a circuit comprising a plurality of interconnected components.

Fig. 1 is a block diagram of a wireless communication system 100 in accordance with the present invention. The system 100 includes a WTRU102, one or more node bs 104, and an RNC 106. The RNC 106 controls overall EU operation by configuring EU parameters for the node-bs 104 and the WTRUs 102, such as maximum allowed EU transmit power or available channel resources for each node-B. The WTRU102 sends a channel configuration request to the node-B104 via an UL EU signaling channel 110, and the node-B104 signals channel configuration information via one or more downlink EU signaling channels 112. After EU radio resources are allocated to the WTRU102, the WTRU102 transmits data over the UL EU channel 110. The node B includes a request priority queue 114 for queuing E-DCH configuration requests and a maximum time timer 116 for configuration to establish an E-DCH configuration request response time period. The WTRU includes a channel allocation response timer 118 for generating periodic channel allocation requests when a channel allocation is not received by the node-B104.

Fig. 2 is a flow chart of a procedure 200 for reducing congestion in the UL EU channel 110 according to an embodiment of the present invention. When the WTRU102 has E-DCH data to transmit, the WTRU102 sends an E-DCH configuration request to the node-B104 via the UL EU channel 110 (step 202), which may be a physical layer signaling or a Medium Access Control (MAC) layer signaling.

Based on the E-DCH configuration request received by the WTRU102, the node-B determines whether available E-DCH resources are available to be allocated to the WTRU within a predetermined channel request response time (step 204), which is a maximum time period for which the node-B104 should respond to the channel configuration request, and when the E-DCH configuration request is received by the node-B104, the established channel request response time, which may be a fixed value in the system or a fixed value for each EU Radio Access Bearer (RAB) configuration by the RNC 106, is started by the maximum time timer 116 for configuration of the node-B104, and signals the node-B104 and the WTRU 102.

If there are available E-DCH resources, the node-B104 sends an acknowledgement message to the WTRU102 indicating that the E-DCH configuration request has been received (step 206) and also sends scheduling information (i.e., E-DCH configuration information) via the DL EU signaling channel within the channel request response time (step 207), and the WTRU102 then transmits data via the UL EU channel 110 according to the scheduling information (step 208).

If the E-DCH resources cannot be configured before the channel request response time expires, the node-B104 sends a confirmation message to the WTRU102 indicating that the E-DCH configuration request has been received but does not send scheduling information to the WTRU102 before the channel request response time expires (step 210), the confirmation message does not contain scheduling information, but merely confirms that the node-B104 has received the channel configuration request and processes the request when resources are available.

According to another embodiment of the invention, the E-DCH configuration request indicates its priority. After sending the confirmation message to the WTRU102 confirming receipt of the E-DCH configuration request, which is stored in a request priority queue 114 of the node-B104 based on the priority indicated by the request (step 212), the maximum time for configuration timer 116 is started after the request is placed in the request priority queue 114 and the time of receipt of the E-DCH configuration request is recorded. The maximum time to configure is a maximum time period during which the E-DCH configuration request should be serviced before the E-DCH configuration request is finally determined to be failed, and may be unique for each transport mapping to a particular data flow or data priority level.

Requests within the request priority queue 114 of the node B104 may be serviced according to a first-in-first-out (FIF0) rule, which further delays the configuration until there are sufficient resources available, if any, until the node B104 services at least one request located in the request priority queue 114.

Based on the confirmation received by the node-B104, the WTRU102 checks whether scheduling information is also received or whether only the channel configuration request is confirmed in response to the received E-DCH configuration request. If the scheduling information is received, the WTRU102 transmits data over the UL EU channel 110 according to the scheduling information indicated by the node-B104 (step 208), and if it is determined that only the E-DCH configuration request is received, the WTRU102 knows that the node-B104 has received the E-DCH configuration request and refrains from retransmitting the same request (step 214).

After the channel allocation request is received and no scheduling information is acknowledged, the node-B104 may later provide EU channel allocation to the WTRU102, which request has been queued in the request priority queue 114 of the node-B104. Periodically, at each Transmission Time Interval (TTI) in step 216, the node B104 determines whether available resources are available for allocation to the requests in the request priority queue 114 (step 218), and the process 200 performs steps 207 and 208 if available.

If no resources are available, the node B104 determines whether the configured maximum time timer 116 expires (step 220).

If the configured max time timer 116 has not expired, as determined in step 220, the process 200 waits for the next TTI in step 216, and the node B104 may configure based on priority that the configured max time is soon to expire.

After the configured maximum time timer 116 expires, i.e., a predetermined period of time has elapsed after the time of receipt of the recorded request, the WTRU102 relies on its channel configuration response timer 118 to track the maximum configuration time period for each E-DCH configuration request, each time the WTRU102 sends an E-DCH configuration request to the node-B104, the WTRU102 sets the channel configuration response timer 118 and recognizes the configuration failure based on the expiration of the channel configuration response timer 118. Otherwise, the node-B104 may notify the WTRU102 of the configuration failure if the WTRU 10-2 does not maintain its own same channel configuration response timer 118, and the node-B104 may not necessarily notify the WTRU102 of the failure if the WTRU102 maintains its own channel configuration response timer 118.

When the E-DCH configuration failure occurs, the WTRU102 has several options and the WTRU102 may retransmit the E-DCH configuration request or an update request to the node-B104 (step 224), which step 224 may be performed periodically each time the channel configuration response timer 118 expires. Otherwise, if the WTRU102 has more E-DCH data to transmit, the WTRU102 may discard the message, wherein the message requests a configuration and sends an update E-DCH configuration request (step 226).

Fig. 3 is a flow chart of a process 300 for determining channel failure for signaling during configuration according to another embodiment of the invention. When the WTRU102 has EU data to transmit, the WTRU102 sends an E-DCH configuration request to the node-B104 and starts the channel configuration response timer 118 (step 302). After sending the E-DCH configuration request, the WTRU102 waits to receive scheduling information (i.e., E-DCH configuration information) from the node-B104 until the channel configuration response timer 118 expires. If the WTRU102 cannot receive scheduling information from the node-B104 before the channel configuration response timer 118 expires (step 304), the WTRU102 retransmits the same E-DCH configuration request with a re-request indicator or an update E-DCH configuration request (step 306).

In this embodiment, the WTRU102 does not know whether the UL EU signaling (i.e., E-DCH configuration request), or the DL EU signaling (i.e., channel configuration) is lost, if the node-B102 receives a retransmission E-DCH configuration request (step 308), the node-B104 determines where the failure occurred (i.e., the E-DCH configuration request on the UL EI channel 110, or the channel configuration via the DL EU signaling channel 112), if the node-B104 receives an E-DCH configuration request that is retransmitted yet to be served, the node B104 determines that the E-DCH configuration request was not successfully transmitted on the UL EU channel 110 (step 314), and the node B104 then takes appropriate corrective action based on the failure of the determination, whether to proceed to step 312 or 314. The node B104 then processes the received request (step 316).

The present invention ensures that the E-DCH configuration request is received by the node B104 when the E-DCH channel configuration is not immediately provided by the node B104 and the EU UL signaling load is minimized, allowing more efficient use of UL physical resources using the method of the present invention.

Although the features and elements of the present invention are described in the embodiments in particular combinations, each feature or element can be used alone without the other features and elements or in various combinations with or without other features and elements of the present invention.

While the invention has been described in terms of preferred embodiments, other variations which do not depart from the scope of the claims herein will become apparent to those skilled in the art.

Claims (29)

1. In a wireless communication system including a wtru and at least one node-B, the channel established between the wtru and the node-B, a method of minimizing utilization of an uplink enhanced uplink channel while maintaining proper enhanced uplink scheduling operations, the method comprising:

(a) the wtru transmitting an e-dch allocation request on the ul eu channel to the node-B;

(b) the node-B receiving the e-dch allocation request and determining whether the e-dch allocation can be provided to the wtru within a predetermined channel request response period;

(c) the node-B sending an acknowledgement message to the wtru indicating that the e-dch allocation request has been received; and

(d) if it is determined in step (B) that the eu-dch allocation cannot be provided to the wtru during the default channel request response period, the node-B stores the eu-dch allocation request in a request priority queue, wherein the wtru refrains from retransmitting the same eu-dch allocation request during the default channel request response period.

2. The method of claim 1 wherein the eDCH allocation request indicates a priority of the request, and the eDCH request is stored in the request priority queue based on the priority indicated by the eDCH allocation request.

3. The method of claim 1, further comprising:

(e) the node B starts a configuration maximum time counter;

(f) the node B determining whether there are available resources to configure the request placed in the queue; and

(g) when the maximum time for configuring the timer expires, the node-B notifies the wtru of a resource allocation failure.

4. The method of claim 1, further comprising:

(e) recording the time when the node B receives the request for configuring the enhanced dedicated channel;

(f) the node B determining whether there are available resources to configure the request placed in the queue; and

(g) after the recording time, the node-B notifies the wtru of a resource allocation failure when a predetermined time expires.

5. The method of claim 1, further comprising:

(e) the wtru starting a channel allocation response timer when the e-dch allocation request is transmitted to the node-B; and

(f) if the channel configuration response timer expires without the node-B sending enhanced dedicated channel configuration information to the wtru, the wtru retransmits the enhanced dedicated channel configuration request to the node-B.

6. The method of claim 5, wherein steps (e) and (f) are performed on a periodic basis.

7. The method of claim 1, further comprising:

(e) upon transmission of the eDCH allocation request to the node-B, the WTRU immediately starts a channel allocation response timer;

(f) the wtru discarding data associated with the enhanced dedicated channel configuration request; and

(g) the wtru transmitting an updated e-dch allocation request on the uplink enhanced uplink channel to the node-B.

8. The method of claim 7, wherein steps (e) and (f) are performed on a periodic basis.

9. The method of claim 1, further comprising:

(e) the node B determining whether there are available resources to allocate to the request placed in the queue;

(f) the node B sending enhanced dedicated channel configuration information to the wtru; and

(g) the wtru transmits enhanced dedicated channel data to the node-B using the resources according to the enhanced dedicated channel configuration information.

10. A wireless communication system, comprising:

(a) a wireless transmit/receive unit, comprising:

(a1) a transmitting device for transmitting an enhanced dedicated channel configuration request;

(b) at least one node B, the node B comprising:

(b1) a maximum time timer for configuring;

(b2) a receiving device for receiving the eDCH allocation request; and

(b3) a configuration request priority queue; and

(c) an uplink enhanced uplink channel established between the wtru and the node-B, wherein:

(i) the wtru transmitting the e-dch allocation request to the node-B on the uplink enhanced uplink channel;

(ii) the node-B receiving the e-dch allocation request and determining whether the e-dch allocation can be provided to the wtru within a predetermined channel request response period established by the timer;

(iii) the node-B sending an acknowledgement message to the wtru indicating that the request for enhanced dedicated channel configuration has been received; and

(iv) if it is determined that the eDCH allocation cannot be provided to the WTRU before the timer expires, the node-B stores the eDCH allocation request in the allocation request priority queue, wherein the WTRU refrains from retransmitting the same eDCH allocation request on the UL eUL channel during the pre-established channel request response.

11. The system of claim 10 wherein the e-dch allocation request indicates a priority of the request, and wherein the e-dch request is stored in the request priority queue based on the priority indicated by the e-dch allocation request.

12. The system of claim 10 wherein the node-B starts the timer, determines whether there are available resources to allocate the queue request, and notifies the wtru of a resource allocation failure when the maximum time to allocate timer expires.

13. The system of claim 10 wherein the timer records the time when the node-B receives the e-dch allocation request, the node-B determines whether there are available resources to allocate the queued request, and the node-B notifies the wtru of a resource allocation failure when a predetermined time determined by the timer elapses after the recorded time.

14. The system of claim 10 wherein the wtru includes a channel configuration response timer that is started when the e-dch configuration request is transmitted to the node-B, and if the channel configuration response timer expires without the node-B sending the e-dch configuration information to the wtru, the wtru retransmits the e-dch configuration request to the node-B.

15. The system of claim 14 wherein the channel configuration response timer is started based on a periodic reference.

16. The system of claim 10 wherein the wtru includes a channel allocation response timer that is started when the eu-dch allocation request is transmitted to the node-B, the wtru discards data associated with the eu-dch allocation request, and the wtru transmits an updated eu-dch allocation request on the ul-eu channel to the node-B.

17. The system of claim 16 wherein the channel configuration response timer is started based on a periodic reference.

18. The system of claim 10 wherein the node B determines that resources are available to configure the queued request, the node B sends enhanced dedicated channel configuration information to the wtru, and the wtru transmits enhanced dedicated channel data to the node B using resources according to the enhanced dedicated channel configuration information.

19. A node B, comprising:

(a) a maximum time timer for configuring;

(b) a receiving device for receiving an enhanced dedicated channel configuration request;

(c) a configuration request priority queue for storing the eDCH configuration request in the configuration request;

(d) means for determining whether the eDCH allocation is available to the WTRU during a predetermined channel request response period defined by the timer; and

(e) a sending device, for sending an acknowledgement message indicating that the eDCH allocation request has been received.

20. The node-B of claim 19 wherein 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.

21. The node-B of claim 19 wherein the node-B starts the timer, determines if there are available resources to allocate the request placed in the queue, and transmits a message indicating that a resource allocation failure occurred when the maximum time to allocate timer expires.

22. The node-B of claim 19 wherein the timer records a time at which the node-B received the e-dch allocation request, the node-B determines whether resources are available to allocate the queued request, and the node-B transmits a message indicating that a resource allocation failure occurred when a predetermined time period determined by the timer elapses after the recorded time.

23. A wireless transmit/receive unit, comprising:

(a) a channel allocation response timer;

(b) a transmission device for transmitting an enhanced dedicated channel configuration request and starting the timer;

(c) means for determining whether an e-dch scheduling message corresponding to the request is received before the timer expires; and

(d) a retransmission unit for retransmitting the request or retransmitting an update eDCH allocation request if the eDCH scheduling information is not received before the timer expires.

24. An integrated circuit, comprising:

(a) a channel allocation response timer;

(b) a transmission device for transmitting an enhanced dedicated channel configuration request and starting the timer;

(c) means for determining whether an e-dch scheduling message corresponding to the request is received before the timer expires; and

(d) a retransmission unit for retransmitting the request or retransmitting an update eDCH allocation request if the eDCH scheduling information is not received before the timer expires.

25. An integrated circuit, comprising:

(a) a maximum time timer for configuring;

(b) a receiving device for receiving an enhanced dedicated channel configuration request;

(c) a configuration request priority queue for storing the eDCH configuration request in the configuration request;

(d) means for determining whether the eDCH allocation is available to the WTRU during a predetermined channel request response period defined by the timer; and

(e) a sending device for sending an acknowledgement message indicating that the eDCH allocation request has been received.

26. In a wireless communication system including a wireless transmit/receive unit (WTRU) and at least one node-B, a method of error isolation enhanced uplink transmission failure, the method comprising:

(a) the wtru transmitting an e-dch allocation request on an uplink enhanced uplink channel to the node-B;

(b) the wtru starting a channel configuration response timer;

(c) the timer expires without the wtru receiving a response to the e-dch configuration request from the node-B;

(d) the wtru retransmitting the e-dch allocation request to the node-B on the uplink eu channel; and

(e) the node-B receives the retransmission request and determines whether the request has been serviced, wherein if the eu-dch allocation request has been serviced, the node-B determines that the channel configuration information sent by the node-B was not successfully delivered to the wtru over the dl eu signaling channel, and if the eu-dch allocation request has not been serviced, the node-B determines that the eu-dch allocation request sent by the wtru was not successfully delivered to the node-B over the ul eu channel.

27. The method of claim 26 wherein the node-B takes corrective action based on which of the uplink and downlink channels prevents a response to the previous request from being received by the wtru.

28. A wireless communication system for error isolating enhanced uplink transmission failures, the system comprising:

(a) a wireless transmit/receive unit;

(b) at least one node B;

(c) an uplink enhanced uplink channel established between the wtru and the node-B; and

(d) a downlink enhanced uplink signaling channel established between the node-B and the wtru;

wherein if the WTRU does not receive a response to a previous request on the DL EU signaling channel, the WTRU retransmits an EU-specific channel configuration request on the UL EU channel;

wherein the node-B determines that the channel configuration information sent by the node-B was not successfully delivered to the WTRU on the DL EU signaling channel if the previous request has been serviced, and determines that the previous request was not successfully delivered to the node-B on the UL EU channel if the EU configuration request has not been serviced.

29. The system of claim 28 wherein the node-B takes corrective action based on which of the uplink and downlink channels prevents a response to the previous request from being received by the wtru.