Communication apparatus and method

• US 7,746,861 B2
• Filed: 08/11/2005
• Issued: 06/29/2010
• Est. Priority Date: 10/19/2004
• Status: Active Grant

• Current Assignee: Palmira Wireless AG
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Tandai, Tomoya, Takagi, Masahiro, Adachi, Tomoko, Utsunomiya, Yoriko, Nishibayashi, Yasuyuki, Nakajima, Tetsu
• Primary Examiner(s): Rao; Seema S
• Assistant Examiner(s): CHAN, SAI MING
• Application Number:
  US11/201,198
• Publication Number:
  US 20060083233A1
• Time in Patent Office: 1,783 Days
• Field of Search: 370/389, 370/428, 370/443, 370/392, 370/469
• US Class Current: 370/392
• CPC Class Codes: H04B 7/2656 for structure of frame, burst
• CPC Class Codes: H04L 1/1621 Group acknowledgement, i.e. the acknowledgement message defining a range of identifiers, e.g. of sequence numbers
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04L 49/9094 Arrangements for simultaneous transmit and receive, e.g. simultaneous reading/writing from/to the storage element
• CPC Class Codes: H04W 80/02 Data link layer protocols

Abstract

A communication apparatus includes a receiving device configured to receive a physical frame in which a plurality of MAC frames, each having a sequence number, are aggregated. A reception buffer which stores MAC frames of the physical frame received by the receiving device. A determination device determines whether or not the first MAC frame in the physical frame received by the receiving device has been successfully received. A reception buffer management device determines, when the first MAC frame has been successfully received, a MAC frame to be forwarded to an upper layer, on the basis of the sequence number of the first MAC frame, and extracts the MAC frame from the reception buffer.

Claims

1. A communication apparatus comprising:

a physical frame transmitting device configured to acquire a channel use permission period and transmit a physical frame to a destination communication apparatus in the channel use permission period, wherein in the physical frame, a plurality of MAC frames, each having a sequence number, are aggregated;

an acknowledgement request frame transmitting device configured to transmit an acknowledgement request frame to the destination communication apparatus, just before the end of the channel use permission period, wherein in the acknowledgement request frame, a starting sequence number of the acknowledgement request frame is set, wherein the acknowledgement request frame is separate from the MAC frames, and wherein all MAC frames stored in a reception buffer of the destination communication apparatus and having a lower sequence number than the starting sequence number set in the acknowledgement request frame are extracted and forwarded to an upper layer.

2. A communication apparatus according to claim 1, wherein when a remaining time of the channel use permission period is not greater than a first threshold, the acknowledgement request frame is transmitted to the destination communication apparatus to forward to the upper layer all the MAC frames stored in the reception buffer.

3. A communication apparatus according to claim 2, wherein the first threshold is determined based on a time required for re-transmitting one or more MAC frames that are transmitted to the destination communication apparatus and that yet have not been successfully received.

4. A communication apparatus according to claim 1, wherein when a remaining time of the channel use permission period is not greater than a first threshold, and the remaining time is greater than or equal to a second threshold, the acknowledgement request frame is transmitted to the destination communication apparatus to forward to the upper layer all the MAC frames stored in the reception buffer.

5. A communication apparatus according to claim 4, wherein the first threshold is determined based on a time required for re-transmitting one or more MAC frames that are transmitted to the destination communication apparatus and that yet have not been successfully received, and

the second threshold is determined based on a time required for transmitting one or more acknowledgement frames for one or more MAC frames to be re-transmitted.

6. The communication apparatus according to claim 1, further comprising a semiconductor integrated circuit including a CPU that executes a firmware.

7. The communication apparatus according to claim 6, wherein the CPU includes at least part of MAC layer function.

8. The communication apparatus according to claim 1, further comprising an antenna, and

wherein the physical frame transmitting device transmits the physical frame and the acknowledgement request frame to a destination communication apparatus via the antenna.