Scheme to prevent HFN un-synchronization for UM RLC in a high speed wireless communication system

• US 20050073987A1
• Filed: 02/25/2003
• Published: 04/07/2005
• Est. Priority Date: 03/28/2002
• Status: Active Grant

• Current Assignee: Innovative Sonic Limited
• Original Assignee: Innovative Sonic Limited
• Inventors: Wu, Chih-Hsiang
• Granted Patent: US 7,298,730 B2
• Time in Patent Office: Days
• US Class Current: 370/349
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0007 by modifying the frame length
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04L 1/1822 involving configuration of automatic repeat request [ARQ] with parallel processes
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 1/1893 Physical mapping arrangements physical resource mapping in general H04L5/00

Abstract

When the system receives a request to switch for using a smaller TBS size, instead of discarding the unacknowledged MAC-hs PDUs, this invention will pick up RLC UM PDUs or RLC AM PDUs or both of them from the unacknowledged MAC-hs PDUs affected by the size change request and reload them into the new PDU. Meantime, this invention will select RLC UM PDUs over RLC AM PDUs to load into the new PDU if the unacknowledged MAC-hs PDU contains both of them. Therefore, this invention reduces the risk of loss of synchronization for UM RLC because the discarding of unacknowledged MAC-hs PDUs according to the prior art.

Claims

1. A method to prevent HFN unsynchronization for UM RLC between a transmitter and a receiver in HSDPA of a high speed wireless communication system;

wherein the transmitter assigns a Transmission Sequence Number (TSN) to each sending data package and temporarily keeps the sent data package until receiving a corresponding response from the receiver, meanwhile due to the change of the communication condition, the system switches to use different sizes of data package—

MAC-hs PDU for transmitting, the method comprising the steps of;

at the transmitter;

receiving a request to switch using a smaller size data package, a new MAC-hs PDU to be transmitted;

until all unacknowledged MAC-hs PDUs have been processed, processing everyone of the unacknowledged MAC-hs PDUs affected by the size change request one at a time with the following steps a to f;

a. extracting subsets from the contains of the unacknowledged MAC-hs PDU;

b. filling up the new MAC-hs PDU with the extracted subsets;

c. assigning the TSN of the unacknowledged MAC-hs PDU to the new MAC-hs PDU;

d. indicating the new MAC-hs PDU containing new data;

e. discarding the extracted unacknowledged MAC-hs PDU; and

f. putting the new MAC-hs PDU ready to be transmitted.

2. The method as claimed in claim 1, wherein the extracted subsets are RLC PDUs containing either RLC UM PDUs or RLC AM PDUs or both of them.

3. The method as claimed in claim 2, wherein indicating the new MAC-hs PDU containing new data comprising the steps of:

setting the value of the New Data Indicator to the value “

0”

for the new MAC-hs PDU if the new MAC-hs PDU is the first MAC-hs PDU transmitted by a HARQ process;

incrementing the value of the New Data Indicator with one for the new MAC-hs PDU if the new MAC-hs PDU is not the first MAC-hs PDU transmitted by a HARQ process; and

assigning the value to the New Data Indicator to the new MAC-hs PDU.

4. The method as claimed in claim 2, extracting subsets from the unacknowledged MAC-hs PDU further comprising the steps of:

selecting the RLC UM PDUs first if the unacknowledged MAC-hs PDU containing such PDUs; and

selecting the RLC AM PDUs if the new MAC-hs PDU has free space and if the unacknowledged MAC-hs PDU containing no RLC UM PDU or all UM PDUs have been extracted.

5. The method as claimed in claim 2, extracting subsets from the unacknowledged MAC-hs PDU further comprising the steps of:

selecting at least one RLC UM PDU from every UM entity first if the unacknowledged MAC-hs PDU containing either both RLC UM PDUs and RLC AM PDUs or RLC UM PDUs only;

afterward selecting RLC PDUs from the rest of the unacknowledged MAC-hs PDU whether they are the RLC UM PDUs or the RLC AM PDUs if the new MAC-hs PDU has free space; and

selecting the RLC AM PDUs if the unacknowledged MAC-hs PDU containing only RLC AM PDUs and if the new MAC-hs PDU has free space.

6. The method as claimed in claim 5, wherein afterward selecting RLC PDUs further comprising of selecting RLC PDUs based on their priority.

7. A system having means for preventing HFN unsynchronization for UM RLC between a transmitter and a receiver in HSDPA of a high speed wireless communication system;

wherein the transmitter assigns a Transmission Sequence Number (TSN) to each sending data package and temporarily keeps the sent data package until receiving a corresponding response from the receiver, meanwhile due to the change of the communication condition, the system switches to use different sizes of data package—

MAC-hs PDU for transmitting, where the transmitter comprising;

means for receiving a request to switch using a smaller size data package, a new MAC-hs PDU to be transmitted;

means for processing every unacknowledged MAC-hs PDUs affected by the size change request;

means for extracting subsets from the contains of the unacknowledged MAC-hs PDU;

means for filling up the new MAC-hs PDU with the extracted subsets;

means for assigning the TSN of the unacknowledged MAC-hs PDU to the new MAC-hs PDU;

means for indicating the new MAC-hs PDU containing new data;

means for discarding the extracted unacknowledged MAC-hs PDU; and

means for putting the new MAC-hs PDU ready to be transmitted.

8. The system as claimed in claim 7, wherein means for extracting subsets

where subsets are RLC PDUs containing either RLC UM PDUs or RLC AM PDUs or both of them.

9. The system as claimed in claim 8, wherein means for indicating the new MAC-hs PDU containing new data further comprising:

means for setting the value of the New Data Indicator to the value “

0”

for the new MAC-hs PDU if the new MAC-hs PDU is the first MAC-hs PDU transmitted by a HARQ process;

means for incrementing the value of the New Data Indicator with one for the new MAC-hs PDU if the new MAC-hs PDU is not the first MAC-hs PDU transmitted by a HARQ process; and

means for assigning the incremented value to the New Data Indicator to the new MAC-hs PDU.

10. The system as claimed in claim 8, means for extracting subsets from the unacknowledged MAC-hs PDU further comprising:

means for selecting the RLC UM PDUs first if the unacknowledged MAC-hs PDU containing such PDUs; and

means for selecting the RLC AM PDUs if the new MAC-hs PDU has free space and if the unacknowledged MAC-hs PDU containing no RLC UM PDU or all UM PDUs have been extracted.

11. The system as claimed in claim 8, means for extracting subsets from the unacknowledged MAC-hs PDU further comprising:

means for selecting at least one RLC UM PDU from every UM entity first if the unacknowledged MAC-hs PDU containing either both RLC UM PDUs and RLC AM PDUs or RLC UM PDUs only;

means for selecting RLC PDUs afterward from the rest of the unacknowledged MAC-hs PDU whether they are the RLC UM PDUs or the RLC AM PDUs if the new MAC-hs PDU has free space; and

means for selecting the RLC AM PDUs if the unacknowledged MAC-hs PDU containing only RLC AM PDUs and if the new MAC-hs PDU has free space.

12. The system as claimed in claim 11, wherein means for selecting RLC PDUs afterward further comprising of selecting RLC PDUs based on their priority.

A transmitter having means for preventing HFN unsynchronization for UM RLC with a receiver in HSDPA of a high speed wireless communication system;

wherein the transmitter assigns a Transmission Sequence Number (TSN) to each sending data package and temporarily keeps the sent data package until receiving a corresponding response from the receiver, meanwhile due to the change of the communication condition, the transmitter switches to use different sizes of data package—

MAC-hs PDU for transmitting, where the transmitter comprising;

means for receiving a request to switch using a smaller size data package, a new MAC-hs PDU to be transmitted;

means for processing every unacknowledged MAC-hs PDUs affected by the size change request;

means for extracting subsets from the contains of the unacknowledged MAC-hs PDU;

means for filling up the new MAC-hs PDU with the extracted subsets;

means for assigning the TSN of the unacknowledged MAC-hs PDU to the new MAC-hs PDU;

means for indicating the new MAC-hs PDU containing new data;

means for discarding the extracted unacknowledged MAC-hs PDU; and

means for putting the new MAC-hs PDU ready to be transmitted.

14. The transmitter as claimed in claim 13, means for extracting subsets from the unacknowledged MAC-hs PDU further comprising:

means for selecting at least one RLC UM PDU from every UM entity first if the unacknowledged MAC-hs PDU containing either both RLC UM PDUs and RLC AM PDUs or RLC UM PDUs only;

means for selecting RLC PDUs afterward from the rest of the unacknowledged MAC-hs PDU whether they are the RLC UM PDUs or the RLC AM PDUs if the new MAC-hs PDU has free space; and