The present invention relates to wireless communication, and in particular to channel selection for uplink and downlink data transmission.
The OSI standard provides a seven-layered hierarchy between an end user and a physical device through which different systems can communicate. Each layer is responsible for different tasks, and the OSI standard specifies the interaction between layers, as well as between devices complying with the standard. The OSI standard includes a physical layer, a data link layer, a network layer, a transport layer, a session layer, a presentation layer and an application layer. The IEEE 802 standard provides a three-layered architecture for local networks that approximate the physical layer, and the data link layer of the OSI standard. The three-layered architecture in the IEEE 802 standard 200 includes a physical (PHY) layer, a media access control (MAC) layer and a logical link control (LLC) layer. The PHY layer operates as that in the OSI standard. The MAC and LLC layers share the functions of the data link layer in the OSI standard. The LLC layer places data into frames that can be communicated at the PHY layer, and the MAC layer manages communication over the data link, sending data frames and receiving acknowledgement (ACK) frames. Together the MAC and LLC layers are responsible for error checking, as well as retransmission of frames that are not received and acknowledged.
The IEEE 802.11e standard (IEEE P802.11e/D13.0 (January 2005), “Amendment: Medium Access Control (MAC) Quality of Service (QoS) Enhancements”), specifies a contention-free medium access control scheme for applications with strict delay requirements. Such a medium access control scheme is a type of time reservation scheme in which an access point (AP) allocates time periods for channel access by different stations (STAs) during a contention-free period. However, currently few manufacturers can support contention-free access control schemes in wireless devices due to implementation complexity. Most IEEE 802.11 wireless local area network (WLAN) devices can only support a contention-based medium access control scheme.
With the proliferation of high quality audio/video (A/V), an increasing number of electronics devices (e.g., consumer electronics devices) utilize high A/V information such as high definition (HD) A/V information. Conventional WLAN IEEE 802.11a/b/g and pre-N wireless devices cannot meet the real-time bandwidth requirements for such high quality A/V transmissions without delay and packet loss. For example, a HD television signal (HDTV) stream of 14 megabits per second (Mbps) over the IEEE 802.11a/g devices with 54 Mbps capacity and over pre-N devices with 108 Mbps, cannot be transmitted from a sender (i.e., source STA) to a receiver (i.e., destination STA) over a wireless channel and played back smoothly. One reason is that for the same application, uplink packets from the sender to the AP, and downlink packets from the AP to the destination, contend the wireless channel simultaneously. This increases packet collisions which causes longer delays, degrading throughout. If acknowledgement packets from the destination to the source are utilized, throughput performance is further degraded. The IEEE 802.11e standard allows a direct link (direct communication) between two STAs without an AP. However, if the two STAs are far apart (i.e., hidden nodes), proper communication between them may not be possible, or the PHY rate capacity of the direct link may be too low to support real-time requirements of HDTV transmissions.
The present invention provides a method and system for alternate wireless channel selection for uplink and downlink data communication. In one embodiment, wireless communication for transmission of data in a network including a relay node comprises, establishing a communication path via the relay node for communication of the data to the relay node and from the relay node; selecting a wireless channel as an uplink channel for uplink transmission of the data to the relay node; and selecting an alternate wireless channel as a downlink channel for downlink transmission of the data from the relay node.
In one implementation, when the network includes plural relay nodes, establishing a communication path further includes establishing a communication path via the multiple relay nodes; and for each relay node in the communication path, selecting a downlink channel for downlink transmission of the data from that relay node comprises selecting a channel as a downlink channel that is alternate to an uplink channel for transmission of the data to that relay node.
An alternate channel selection scheme according to the present invention avoids contention for the same channel between uplink and downlink transmissions of the same data communication application. One application involves wireless transmission of audio/video information such as high definition digital video information.
These and other features, aspects and advantages of the present invention will become understood with reference to the following description, appended claims and accompanying figures.
The present invention provides a method and system for alternate wireless channel selection for uplink and downlink data communication. In one embodiment, according to the alternate channel selection scheme, two different channels are selected at a relay node, one channel for uplink transmission from a source station (sender) to the relay node, and another channel for downlink transmissions from the relay node to a destination/sink station (receiver). Such an alternate channel selection scheme avoids contention for the same channel between uplink and downlink transmissions of the same data communication application.
Each relay node implements the alternate channel selection scheme and accordingly selects different, independent, channels for uplink and downlink transmissions of the same application which may require transfer of large amounts of data from a source to a destination in a network.
One application of the alternate channel selection scheme is in real-time transmissions such as A/V streaming in a wireless network. This allows satisfaction of real-time communication requirements such as Quality of Service (QoS) requirements in data rate A/V applications (e.g., a HDTV stream).
In many wireless communication systems, a frame structure is used for data transmission between wireless stations such as a transmitter (sender) and a receiver. For example, the IEEE 802.11 standard uses frame aggregation in a Media Access Control (MAC) layer and a physical (PHY) layer. In a typical transmitter, a MAC layer receives a MAC Service Data Unit (MSDU) and attaches a MAC header thereto, in order to construct a MAC Protocol Data Unit (MPDU). The MAC header includes information such a source addresses (SA) and a destination address (DA). The MPDU is a part of a PHY Service Data Unit (PSDU) and is transferred to a PHY layer in the transmitter to attach a PHY header (i.e., PHY preamble) thereto to construct a PHY Protocol Data Unit (PPDU). The PHY header includes parameters for determining a transmission scheme including a coding/modulation scheme. Before transmission as a packet from a transmitter to a receiver, a preamble is attached to the PPDU, wherein the preamble can include channel estimation and synchronization information.
Using the functionality of the unified MAC coordinator 22, the relay node 32 implements multi-channel communication for uplink and downlink transmissions by selecting different (i.e., alternate) channels for uplink transmission (e.g., IEEE 802.11a) from the sender 34 to the relay node 32 and downlink transmission (e.g., IEEE 802.11b/g) from the relay node 32 to the receiver 36, for the same application provided that different channels are available to the relay node 32 for uplink and downlink communication, as described further below.
The receiving relay node appends the channel number to the request message (step 53) and then checks whether the receiver is within the same subnet as the receiving relay node (step 54). All devices within one subnet can hear (communicate with) each other. If the receiver is within the same subnet, then the receiving relay node checks if the current channel number between the receiving relay node and the receiver is different from all channel numbers recorded in the request message (step 55). If different channels, the receiving relay node then forwards the virtual connect request message downlink to the receiver on the current channel (step 56). At this point a virtual connection link path (communication path) via one or more relay nodes is established and the process then proceeds to step 66. Otherwise, the receiving relay node selects a different channel between the receiving relay node and the receiver (step 57), and then forwards the setup request downlink to the receiver on the new channel (step 58). At this point a virtual connection link path is established, and the process then proceeds to step 66.
If in step 54, the receiving relay node finds that the receiver is not in the same subnet, then the receiving relay node checks if the current channel between the receiving relay node and a next relay node is different from all channel numbers recorded in the request message (step 59). If different channels, then the receiving relay node forwards the virtual connection request message downlink to the next relay node (step 60). Otherwise, the receiving relay node determines if a different channel for communication between the receiving relay node and the next relay node, different from all the channels recorded in the request message, is available for selection (step 61). If a different channel is available, then the receiving relay node selects a different channel between the receiving relay node and the next relay node (step 62), and then forwards the virtual connection request message downlink to the next relay node using the new channel (step 63). The process then proceeds back to step 52 where the next relay node receives the forwarded virtual connection request message uplink and takes the role of a receiving relay node.
If in step 61 the receiving relay node cannot find a new channel different from all those recorded in the request message, then the receiving relay node selects a channel number with less/minimal possibility of interference with those channels recorded in the virtual connect request message (e.g., a channel that is least frequently used and/or appeared earliest in the virtual connection request message) (step 64). Then, the receiving relay node forwards the virtual connection request message to the next relay node uplink using the newly selected channel (step 65). The process then proceeds back to step 52 where the next relay node receives the forwarded virtual connection request message uplink and takes the role of a receiving relay node.
In step 66, upon receiving the virtual connection request message, the receiver sends back a control message confirming a virtual connection confirmation to the sender. Control messages are sent back on the same channel as a forward channel since it is a bi-directional channel. After the sender receives the virtual connection confirmation, the sender starts transmitting data to the receiver using the established virtual connection link path. The virtual link path is a set of connections from the sender to the receiver via a chain of one or more relay nodes, wherein each relay node selects a downlink channel that is different from the uplink channel to that relay node. Preferably, each relay node selects a downlink channel that is different from the downlink channels selected by prior relay nodes, provided such a different downlink channel is available.
Using an alternate wireless channel selection for uplink and downlink real-time data communication according to the present invention improves channel bandwidth allocation efficiency, and reduces packet loss and end-to-end delay/jitter are reduced. Further, performance degradation due to hidden nodes is reduced. The present invention also allows real-time support for data communication with contention-based channel access control such as in A/V applications over 2.4 GHz or 5 GHz Wireless Local Area Networks (WLANs). The present invention is also useful with Wireless HD (WiHD) applications. Wireless HD is an industry-led effort to define a wireless digital network interface specification for wireless HD digital signal transmission on the 60 GHz frequency band, e.g., for consumer electronics (CE) and other electronic products. An example WiHD network (e.g., implemented in
As is known to those skilled in the art, the aforementioned example architectures described above, according to the present invention, can be implemented in many ways, such as program instructions for execution by a processor, as logic circuits, as an application specific integrated circuit, as firmware, etc. The present invention has been described in considerable detail with reference to certain preferred versions thereof; however, other versions are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein.
Number | Name | Date | Kind |
---|---|---|---|
5999127 | Dezelan | Dec 1999 | A |
6526036 | Uchida et al. | Feb 2003 | B1 |
6865609 | Gubbi et al. | Mar 2005 | B1 |
6934752 | Gubbi | Aug 2005 | B1 |
6961316 | Yamaguchi et al. | Nov 2005 | B2 |
7221680 | Vijayan et al. | May 2007 | B2 |
7450610 | An | Nov 2008 | B2 |
7499462 | MacMullan et al. | Mar 2009 | B2 |
7508781 | Liu et al. | Mar 2009 | B2 |
7564862 | Srikrishna et al. | Jul 2009 | B2 |
7570627 | Welborn et al. | Aug 2009 | B2 |
7653030 | Arrakoski et al. | Jan 2010 | B2 |
7920540 | Singh et al. | Apr 2011 | B2 |
7936782 | Qin et al. | May 2011 | B2 |
8031666 | Jeon et al. | Oct 2011 | B2 |
20020114295 | Takahiro et al. | Aug 2002 | A1 |
20040029591 | Chapman et al. | Feb 2004 | A1 |
20040072573 | Shvodian | Apr 2004 | A1 |
20040139477 | Russell et al. | Jul 2004 | A1 |
20050053015 | Jin et al. | Mar 2005 | A1 |
20050141451 | Yoon et al. | Jun 2005 | A1 |
20050152394 | Cho | Jul 2005 | A1 |
20050188073 | Nakamichi et al. | Aug 2005 | A1 |
20060009229 | Yuan et al. | Jan 2006 | A1 |
20060013171 | Ahuja et al. | Jan 2006 | A1 |
20060056316 | Chandra et al. | Mar 2006 | A1 |
20060120324 | Cho et al. | Jun 2006 | A1 |
20060164969 | Malik et al. | Jul 2006 | A1 |
20060209892 | MacMullan et al. | Sep 2006 | A1 |
20070140273 | Kubota | Jun 2007 | A1 |
20070230338 | Shao et al. | Oct 2007 | A1 |
20070253388 | Pietraski | Nov 2007 | A1 |
20070253391 | Shao et al. | Nov 2007 | A1 |
20080019305 | Dekorsy et al. | Jan 2008 | A1 |
20090232103 | Kesselman et al. | Sep 2009 | A1 |
20100226343 | Hsu et al. | Sep 2010 | A1 |
Number | Date | Country |
---|---|---|
1478135 | Nov 2004 | EP |
1484867 | Dec 2004 | EP |
2000236338 | Aug 2000 | JP |
2003274446 | Sep 2003 | JP |
2004128654 | Apr 2004 | JP |
2005027298 | Jan 2005 | JP |
2007019604 | Jan 2007 | JP |
2008512040 | Apr 2008 | JP |
2005089358 | Sep 2005 | WO |
2006025773 | Mar 2006 | WO |
2007111474 | Oct 2007 | WO |
Entry |
---|
IEEE Computer Society, “Part 15.3: Wireless Medium Access Control (MAC) and Physical Layer (PHY) Specifications for High Rate Wireless Personal Area Networks (WPANs),” IEEE, Sep. 29, 2003, pp. 1-315, New York, United States. |
IEEE P802.11e/D13.0 (Jan. 2005), “Amendment: Medium Access Control (MAC) Quality of Service (QoS) Enhancements,” pp. 1-198. |
IEEE Wireless LAN Edition (2003), “A compilation based on IEEE Std 802.11TM-1999 (R2003) and its amendments,” Sep. 19, 2003, pp. 1-706. |
Stephens, A; and Coffey, S., “Joint Proposal: High throughput extension to the 802.11 Standard: MAC,” doc.: IEEE 802.11-05/1095r2, Nov. 16, 2005, pp. 1-37. |
U.S. Non-final Office Action for U.S. Appl. No. 11/787,576 mailed Apr. 29, 2010. |
Japanese Office Action dated May 8, 2012 for Japanese Patent Application No. 2009-502674 from Japanese Patent Office, pp. 1-2, Tokyo, Japan. |
U.S. Notice of Allowance for U.S. Appl. No. 11/787,576 mailed Aug. 2, 2012. |
Hitachi, Ltd. et al., “High-Definition Multimedia Interface Specification Version 1.2,” HDMI Licensing, LLC, Aug. 22, 2005, pp. i-110 and CEC-i-CEC-84, United States. |
IEEE Computer Society, “IEEE Std 802.15.3TM-2003 IEEE Standard for Information Technology—Telecommunications and information exchange between systems—Local and metropolitan area networks—Specific requirements, Part 15.3: Wireless Medium Access Control (MAC) and Physical Layer (PHY) Specifications for High Rate Wireless Personal Area Networks (WPANs),” IEEE, Sep. 29, 2003, pp. i-315, New York, United States. |
Van Veen, B.D. et al., “Beamforming: A Versatile Approach to Spatial Filtering,” IEEE ASSP Magazine, vol. 5, No. 2, IEEE, Apr. 1988, pp. 4-24, New York, United States. |
Zhu, H. et al., “A Power-Aware and QoS-Aware Service Model on Wireless Networks,” 23rd Annual Joint Conference of the IEEE Computer and Communication Societies (INFOCOM 2004), vol. 2, IEEE, Mar. 2004, pp. 1393-1403, United States. |
Chinese Notice of Allowance dated Feb. 25, 2011 for Chinese Patent Application 200780008339.4 from the China Intellectual Property Office, pp. 1-2, China Intellectual Property Office, People's Republic of China (English Translation attached, pp. 1-2). |
Chinese Office Action dated Aug. 30, 2010 for Chinese Patent Application 200780008339.4 from the China Intellectual Property Office, pp. 1-3, China Intellectual Property Office, People's Republic of China (A machine-generated English Translation attach, pp. 1-6). |
U.S. Non-final Office Action for U.S. Appl. No. 11/726,779 mailed Oct. 20, 2010. |
U.S. Non-final Office Action for U.S. Appl. No. 11/726,779 mailed Mar. 30, 2011. |
U.S. Final Office Action for U.S. Appl. No. 11/726,779 mailed Oct. 11, 2011. |
U.S. Notice of Allowance for U.S. Appl. No. 11/726,779 mailed Jan. 20, 2012. |
U.S. Final Office Action for U.S. Appl. No. 11/787,576 mailed Sep. 13, 2010. |
European Search Report dated Feb. 27, 2012 for European Application No. EP 07746593, pp. 1-7, European Patent Office, Munich, Germany. |
Kim, J.E. et al., “An Improvement of Channel Efficiency for IEEE 802.15.3 High Rate WPAN”, Proceedings of the 2006 International Conference on Advanced Communication Technology (ICACT), Feb. 20, 2006, pp. 1677-1680, vol. 3, IEEE, United States. |
Rangnekar, A. et al., “QoS Aware Multi-Channel Scheduling for IEEE 802.15.3 Networks”, Feb. 1, 2006, pp. 47-62, vol. 11, No. 1, Kluwer Academic, United States. |
Gilb, J.P.K. et al., “Proposal for Wireless support of uncompressed HD audio and video using 60 GHz unlicensed band”, Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs), Mar. 13, 2007, pp. 1-15, IEEE, United States. |
Chinese Office Action dated Dec. 31, 2011, for Chinese Patent Application 200780052615.7 from China Intellectual Property Office, pp. 1-24, China Intellectual Property Office, People's Republic of China (Machine-generated English-language translation attached, pp. 1-10). |
European Search Report dated Mar. 12, 2012 for European Patent Application No. 07746593.8 from European Patent Office, pp. 1-6, Munich, Germany. |
Japanese Office Action dated Mar. 29, 2012 for Japanese Patent Application No. 2010-503951 from Japanese Patent Office, pp. 1-9, Tokyo, Japan (English-language translation attached, pp. 1-5). |
Chinese Office Action dated Sep. 29, 2012 for Chinese Patent Application No. 200780052615.7 from Chinese Patent Office, pp. 1-35, China Intellectual Property Office, People's Republic of China (English-language translation attached, pp. 1-21). |
Chinese Office Action dated Mar. 1, 2013 for Chinese Patent Application 200780052615.7 from China Intellectual Property Office, pp. 1-39, China Intellectual Property Office, People's Republic of China (Machine-generated English-language translation attached, pp. 1-25). |
European Search Report dated Dec. 13, 2012 for European Application No. EP 07745674.7, pp. 1-8, European Patent Office, Munich, Germany. |
Korean Office Action dated Sep. 2, 2013 for Korean Patent Application No. 10-2008-7007687 from Korean Intellectual Property Office, pp. 1-15, Seo-gu, Daejeon, Republic of Korea (Machine-generated English-language translation attached, pp. 1-10). |
Number | Date | Country | |
---|---|---|---|
20090080366 A1 | Mar 2009 | US |