WO2009014504A1

WO2009014504A1 - Wireless local area networking devices providing quality of service based on packet content transmitted over local area networks

Info

Publication number: WO2009014504A1
Application number: PCT/TR2008/000053
Authority: WO
Inventors: Metin Ismail Taskin; Firat Birlik; Ozgur Ercetin; Ozgur Gurbuz
Original assignee: Airties Kablosuz Iletisim Sanayi Ve Dis Ticaret As
Priority date: 2007-07-25
Filing date: 2008-05-13
Publication date: 2009-01-29
Also published as: TR200705158A2

Abstract

This invention is related to Automatic Classification and Prioritization Software and Wireless Local Area Networking devices that can run this software in order to enable wireless transmission of voice or video packets at required quality by classifying packets. Those devices can form IEEE 802.11s Standard compliant wireless mesh networks and transfer voice and video or like signals at high quality by forming the said IEEE 802.11s Standard compliant wireless mesh networks in order to overcome wireless signal attenuation problems encountered in concrete buildings. The devices invented may also include VoIP, IPTV or DSL modem features integrated in the same hardware.

Description

WIRELESS LOCAL AREA NETWORKING DEVICES PROVIDING QUALITY OF SERVICE BASED ON PACKET CONTENT TRANSMITTED OVER LOCAL AREA NETWORKS

SUBJECT OF THE INVENTION

This invention is related to Automatic Classification and Prioritization Software and

Wireless Local Area Networking devices that can run this software on, which enable wireless transmission of voice or video packets at required quality. Those devices can form IEEE 802.11s Standard compliant wireless mesh networks and transfer voice and video or like signals at high quality by forming the said IEEE 802.11s Standard compliant wireless mesh networks in order to overcome wireless signal attenuation problems encountered in concrete buildings. The devices invented may also include VoIP, IPTV or DSL modem features integrated in the same hardware.

THE OBJECTIVES OF THE INVENTION

The objectives of developing Automatic Classification and Prioritization Software and Wireless Local Area Networking devices that can run this software on are:

• Transfer voice, video and data over Wireless Local Area Networks (WLANs) with high ' quality.

• Eliminate the need for multiple communication networks for voice, video and data transfer.

• By transmitting TV and video signals wirelessly from broadband gateway to the TV receiver in home, eliminate in home wiring costs of especially for IPTV service providers who provide TV and video service over Internet.

• By forming IEEE 802.11s compliant wireless mesh Networks, eliminate wireless signal attenuation effects in concrete buildings, increase wireless coverage area and eliminate cable necessity in order to transfer voice, video and data with high quality

• While increasing wireless coverage area, increase voice and video quality that cannot be provided by standard 802.11 based technology because of increasing number of mesh links PRIOR ART

IEEE 802.11 (802.11) also known as Wi-Fi, is a combination of wireless network protocols which is developed by the 11th Working Group of IEEE LAN/MAN (Local Area Networks/Metropolitan Area Networks) Standards Committee. 802.11 protocol family combines many modulation techniques with a shared medium access protocol CSMA/CA (Carrier Sense

Multiple Access with Collision Avoidance).

802.11 defines several sub standards like 802.11b, 802. Hg, 802.11a and 802.Hn having different physical layer characteristics such as transmission rates and different CSMA/CA parameters like slot time, back-off durations and retry periods. 802.11b standard supports physical transmission rates 11, 5.5, 2 and 1 Mbps whereas 802.11a/g standards support 54, 48, 36, 24, 18, 12, 9, 6 Mbps. 802.Hn standard is currently not finalized yet, but it promises 3-4 times higher physical transmission rates compared to 802.11a and 802. Hg.

In all 802.11 standards, there are dramatical differences between physical transmission .rates and actual achievable data throughput. For example 802.Hb supports HMbps as the ' highest physical transmission rate while 802.Hb can achieve maximum data throughput of about < 5Mbps. Similarly 802.11a/g support 54Mbps as the highest physical transmission rate, while these standards can only achieve 20-25 Mbps actual data throughputs.

According to the channel access technique CSMA/CA, employed by 802.11, wireless channel is a shared medium among users. At a given time, only a single node can transmit data to the channel; so formerly mentioned maximum achievable throughput values are shared among each transmitting node. For a single node to achieve these transmission speeds, there should be no other transmitting node in the same and overlapping channels.

According to CSMA/CA technique, wireless clients listen to the channel before initiating any transmission. If the channel is idle and this is the first try for transmission by the client, transmission is started immediately. If the channel is busy, client should wait until the channel is idle again. If it is a retry for the same transmission or client is waiting for the channel to become idle; client should back-off a random amount of time according to exponential back-off algorithm defined in the 802.11 standard. After this time period, if the channel is busy the back-off cycle is repeated. If the channel became idle, client starts the transmission. Durations that are randomly generated by exponential back-off algorithm are calculated using the units of slot time that is defined in the 802.11 standard. For this calculation Contention Window (CW) minimum and maximum values are used. For choosing the back-off duration, a random integer between CW_min and CW_max is picked. The amount of slots that client should wait before transmission is calculated as two to the power of this number slots added to a predefined constant. In 802.11b and 802.11b/g mixed mode standards, a slot time is defined as 20 μs, while in 802.11a and 802. Hg standards it is defined as 9 μs.

In formerly stated 802.11 standards, medium access control layer only differs by several predefined values and do not have a structure that allows traffic in different qualities. So 802.11 mac is not designed to support any quality of service guarantees or resource reservation; thus voice, video and data traffic are sent with the same priority without any differentiation. As a result, voice and video transmissions with certain delay and bandwidth requirements suffer quality degradation while transmitted over 802.11 shared medium.

To handle the lack of quality of service support in 802.11 mac, IEEE 802.He (802.He) is introduced. In 802. He, different traffic classes with different priorities are defined, but no mechanism is introduced to support quality of service guarantees. 802.He traffic classes are ' differentiated with different CW_min and CW_max values that are defined in CSMA/CA algorithm.

If a node picks random back-off durations from a smaller number pool compared to other nodes. , t it has a better chance to win the contention and to start transmission. So four different traffic ^' classes with varying priorities (19,20,21,22) are defined in 802.He (18) with different CW values. These traffic classes are from lowest priority to highest priority as follows: Background (BG) (19), Best Effort (BE) (20), Video (Vl) (21) and Voice (VO) (22).

Even 802.He defines several traffic classes, there is no definition how various traffics are mapped to these access categories. Besides that, these traffic classes only differentiate how available resources are shared among these classes. So even if the priority of a access category is very high, it is possible that resources left to the high priority client is not enough. Especially in wireless mesh networks, a packet is transmitted over several nodes till it reaches the final destination; so end-to-end delay and end-to-end throughput will be relatively lower compared to a single transmission.

Wireless Distribution System (WDS) is a 802.11 mac extension to support direct communication between wireless access points; so communication between clients connected to different access points can be relayed using wireless links between access points. A wireless network topology that consists of wireless interconnected access points for relaying traffic of clients connected to different parts of the network is called wireless mesh networks. WDS connections in a wireless mesh network are called mesh links. The path between two clients consisting of mesh links and mesh nodes is called a mesh path or a mesh route. To discover mesh routes, various algorithms can be used. In standard 802.11 packet transfers, each client has the same probability for transmission. In mesh routes, for a successful end-to-end transmission, the same packet has to be transmitted over the wireless channel several times, thus diminishing the actual priority of the packet.

IEEE 802.11s (802.11s) is a working group for defining the standard for wireless mesh networks. 802.11s is a standard for 802.11 devices that lets each device to detect its neighbors and form a wireless mesh network automatically. 802.11s also supports dynamic topology changes, automatic configuration, automatic healing of the wireless mesh network, routing algorithms and power saving features. It is not known when the 802.11s draft will be finalized.

Wireless Mesh Networks (WMN) can discover alternative higher performance paths compared to the direct connections that are weakened because high attenuation caused by high distance and concrete walls (4) in indoor environments. On the other hand, with each traversed mesh link, delay and loss probabilities of packets will be accumulated. Accumulated high delay^* and high packet loss degrades quality of video and voice transmission. Transmissions by other nodes in the same channel also have a negative impact on these multimedia transmissions, while . minimizing the end-to-end performance between clients.

In order to avoid delay and packet loss that inhibits a proper high quality voice or video transmission, these packets should be served with required low delay and packet loss. Unlike a data transmission, a delay in the order of milliseconds may degrade the quality of video or voice transmission.

Voice, video and even data transfers suffer higher delays and packet losses because of the multi hop nature of the wireless mesh networks. Besides that, a single hop 802.11 transmission also lacks the required low delay and low packet loss requirements of a voice and video transmission.

In this invention 802. lie and 802.11s are used, but unlike the previous techniques, a new algorithm is designed, that inspects and classifies voice and video packet on the network equipments and sends these packets with required priority to support high quality voice and video transmission over wireless mesh networks. With this invention, it is made possible to stream high quality voice and video while supporting data traffic over the same wireless network.

By this way, users can not only transmit video and video with quality but also can exchange data at the same time. DESCRIPTION OF THE FIGURES AND THE COMPONENTS

The attached figures are presented to better describe the Automatic Classification and Prioritization Software and Wireless Local Area Networking devices that can run this software on, proposed in this invention. Figure 1 shows an example usage scenario of devices utilizing Automatic Classification and Prioritization Software described in this invention. Figure 2 shows an example block diagram of a device utilizing Automatic Classification and Prioritization Software and having capability of forming mesh networks. Figure 3 shows the algorithm of Automatic Classification and Prioritization Software. The figures are further explained below:

Figure 1 - An example usage scenario

Figure 2 - An example block diagram of a device utilizing Automatic Classification and Prioritization Software and having capability of forming mesh networks

¹ Figure 3 - Flow diagram of Automatic Classification and Prioritization algorithm

In order to explain this invention, all the components that appear in the figures are- numbered separately and the description of every numbered item is given below.

1. Wireless mesh points that support Automatic Classification and Prioritization

2. Wireless Modem supporting Automatic Classification and Prioritization

3. Wireless mesh link with high performance

4. Thick wall that is degrading wireless link

5. A low performing mesh link that is weakend by of thick walls and long distance

6. Wireless client links

7. Computers with wireless links (Video/voice/data clients)

8. Digital video receiver

9. Television, projector etc. 10. VoIP telephone (Voice client)

11. Internet

12. Data Server (web, ftp, e-mail etc. servers)

13. Digital video server (Video provider) 14. VoIP server (Voice communication provider)

15. Automatic Classification and Prioritization module

16. Network layer of operating system

17. 802.11 wireless connection module

18. 802. lie service quality layer 19. 802. lie Traffic Queue #0, Low priority background traffic

20. 802. lie Traffic Queue #1, Normal priority traffic

21. 802.11e Traffic Queue #2, High priority traffic

22. 802.11e Traffic Queue #3, Highest priority traffic

23. 802.11 device radio module 24. 802.11 device radio antenna module

25. Mesh module

26. Ethernet module

27. Ethernet cable

28. Start Automatic Classification and Prioritization Algorithm 29. Capture packets that will be transmitted over 802.11 module

30. Check if it is a video packet

31. Check if the video packet type is predefined

32. Label video packet related to its packet type priority 33. Label video packet with predefined priority

34. Check if it is a voice packet

35. Check if the Voice packet type is predefined

36. Label voice packet related to its packet type priority 37. Label voice packet with its predefined priority

38. Check if it is a specially defined packet

39. Label specially defined packet per predefined priority value

40. Label per normal traffic class

41. Classify and transmit based on priority defined in packet label 42. End of Automatic Classification and Prioritization algorithm

DETAILED DESCRIPTION OF THE INVENTION

Wireless Local Area Networking devices that can run this software on, which enable wireless transmission of voice or video packets at required quality. By examining packets traveling across wireless networks, they enable high quality voice and video packet transmission based on packet content. The devices that contain this software defined in this invention also overcome radio signal attenuation and wireless coverage problems caused by thick walls by forming 802.11s standard compliant wireless mesh networks. By Automatic Classification and Prioritization Software and 802. lie standard compliance, they provide high quality voice and video transfer, where standard 802.11 devices are not capable of. The devices in this invention may also have

VoIP, IPTV and DSL modem features integrated.

The wireless devices(l,2) utilizing Automatic Classification and Prioritization Software inspect and label the packets in order to put them in the appropriate queue with priority levels defined in IEEE 802. lie (18) standard. Labeled video and voice packets are transmitted through wireless mesh networks at a priority level as defined in IEEE 802. lie standard. Thus priority level of video, voice and data packets lost in multiple mesh links are also restored by using 802. lie (18) mechanism. The new priority levels assigned to each packet make sure that the delay and packet loss requirements of video and voice are fulfilled. Fair usage of wireless link capacity between the wireless mesh links (3, 5) is changed to the advantage of video and voice packets passing over the wireless mesh links (3, 5). That way, high quality voice and video transmission over wireless mesh networks is achieved.

Automatic Classification and Prioritization Software(15) consists of two main components: classifier (30,34,38) and labeler (32,33,36,37,39,40). There are separate modules for voice packet classification (34) and video packet classification (30) and there is a special packet classification module (38) for classifying other specific packets requiring specific priority. If a packet is classified in one category, then more detailed classification module (31, 35) re-inspects the same packet and labels it with a predetermined priority value. Labelled packets are released to 802.11 module for transmission (41).

Automatic Classification and Prioritization Software starts (28). Packets that will be transferred over 802.11 interface (17) are captured (29). A packet to be transferred is checked if it can be classified as a video packet of any kind of video transmission format based on packet header, content, relation to previous or future packets or any other attribute required by any video transmission formats (30). If the packet is classified as a video packet, detailed classification of that packet is also done based on packet header, content, relation to previous or future packets or any other attribute required by any video transmission format (31). If detailed classification is successful, the classified video packet is labeled as a predetermined traffic class for its type (32) or a traffic class that is created based on the conditions present at that moment (33). 802.11 module (17) transmits the packet with the priority of traffic class that is specified in the label on the packet (41).

If the packet to be transferred can not be classified as video packet, it is checked if it can be classified as a voice packet of any kind of voice transmission format based on packet header, content, relation to previous or future packets or any other attribute required by any voice transmission format (34). If the packet is classified as voice packet, detailed classification of that packet is also done based on packet header, content, relation to previous or future packets or any other attribute required by any voice transmission format (35). If detailed classification is successful, the classified voice packet is labeled as a predetermined traffic class for its type (37) or a traffic class that is created based on the conditions present at that moment (36). 802.11 module

(17) transmits the packet with the priority of traffic class that is specifieded in the label on the packet (41).

If the packet to be transferred can not be classified as video or voice packet, it is checked if it can be classified as a specially defined packet based on packet header, content, relation to previous or future packets or any other attribute required by special packet format (38). If the packet is classified as specially defined packet, it is labeled with its predetermined traffic class (39). 802.11 module (17) transmits the packet with the priority of traffic class that is specified in the label on the packet (41).

If the packet to be transferred can not be classified as video, voice or special packet, it is labeled (40) as normal traffic class (20) and transmitted (41) over 802.11 module (17) with 802. lie normal traffic class priority (18). The priority of this class is the same as unprioritized packets or packets transmitted by ordinary 802.11 devices which do not utilize 802. lie classification. The packets that will be transmitted in this class have the same priority as of packets from other clients in the environment.

The labeled packets to be transmitted are ready for transmission with the priority of their traffic class. These packets are assigned to 802. lie (18) classes (19,20,21,22) based on traffic class values specified in their labels and they are transmitted (41) by 802.11 module (17) according the their priority level. Automatic Classification and Prioritization Software ends for labeled and transmitted packets (42). Automatic Classification and Prioritization Software is rerun for every packet that is queued to be transmitted over 802.11 module (17).

The advantage of this invention is that it enables transferring voice, video and data packets over the a single 802.11 compliant wireless network and maintain high video and voice quality. Thus video and voice over internet protocol services such as IPTV and VoIP can be distributed wirelessly inside home or office without needing any cables. Automatic Classification and Prioritization Software realized in this invention runs without the need of any new configuration and it guarantees the quality needed for voice and video packet transmission.

Claims

1. Automatic Classification and Prioritization Software and Wireless Local Area Networking devices that can run this software on enabling high quality voice and video packet transmission based on packet content by examining packets traveling across wireless networks.

2. Being described in claim 1, Automatic Classification and Prioritization Software and Wireless Local Area Networking devices that can run this software on, characterized as overcoming radio signal attenuation and wireless coverage problems caused by thick walls by forming 802.11s standard compliant wireless mesh networks and by Automatic Classification and

Prioritization Software and 802. lie standard compliance, providing high quality voice and video transfer, where standard 802.11 devices are not capable of.

3. Being described in any claims above, Automatic Classification and Prioritization Software and Wireless Local Area Networking devices that can run this software on, characterized as having . VoIP, IPTV and DSL modem features integrated.

4. Being described in any claims above, Automatic Classification and Prioritization Software and Wireless Local Area Networking devices that can run this software on, characterized as inspecting and labeling the packets in order to put them in the appropriate queue with priority levels defined in IEEE 802.11e (18) standard.

5. Being described in any claims above, Automatic Classification and Prioritization Software and Wireless Local Area Networking devices that can run this software on, characterized as labeled video and voice packets are transmitted through wireless mesh networks at a priority level as defined in IEEE 802.11e standard.

6. Being described in any claims above, Automatic Classification and Prioritization Software and Wireless Local Area Networking devices that can run this software on, characterized as priority level of video, voice and data packets lost in multiple mesh links are also restored by using 802. lie (18) mechanism.

7. Being described in any claims above, Automatic Classification and Prioritization Software and Wireless Local Area Networking devices that can run this software on, characterized as the new priority levels assigned to each packet make sure that the delay and packet loss requirements of video and voice are fulfilled.

8. Being described in any claims above, Automatic Classification and Prioritization Software and Wireless Local Area Networking devices that can run this software on, characterized as fair usage of wireless link capacity between the wireless mesh links (3, 5) is changed to the advantage of video and voice packets passing over the wireless mesh links (3, 5), and that way, high quality voice and video transmission over wireless mesh networks is achieved.

9. Being described in any claims above, Automatic Classification and Prioritization Software and Wireless Local Area Networking devices that can run this software on, characterized as Automatic Classification and Prioritization Software consisting of two main components: classifier (30,34,38) and labeler (32,33,36,37,39,40).

10. Being described in any claims above, Automatic Classification and Prioritization Software and Wireless Local Area Networking devices that can run this software on, characterized as there are separate modules for voice packet classification (34) and video packet classification (30) and there is a special packet classification module (38) for classifying other specific packets requiring specific priority.

11. Being described in any claims above, Automatic Classification and Prioritization Software and Wireless Local Area Networking devices that can run this software on, characterized as if a packet is classified in one category, then more detailed classification module (31, 35) . re- inspects the same packet and labels it with a predetermined priority value and labelled packets are released to 802.11 module for transmission (41).

12. Being described in any claims above, Automatic Classification and Prioritization Software and Wireless Local Area Networking devices that can run this software on, characterized as Automatic Classification and Prioritization Software starts (28), packets that will be transferred over 802.11 interface(17) are captured (29), a packet to be transferred is checked if it can be classified as a video packet of any kind of video transmission format based on packet header, content, relation to previous or future packets or any other attribute required by any video transmission formats (30)

13. Being described in any claims above, Automatic Classification and Prioritization Software and

Wireless Local Area Networking devices that can run this software on, characterized as if the packet is classified as a video packet, detailed classification of that packet is also done based on packet header, content, relation to previous or future packets or any other attribute required by any video transmission format (31).

14. Being described in any claims above, Automatic Classification and Prioritization Software and Wireless Local Area Networking devices that can run this software on, characterized as if detailed classification is successful, the classified video packet is labeled as a predetermined traffic class for its type (32) or a traffic class that is created based on the conditions present at that moment (33) and 802.11 module (17) transmits the packet with the priority of traffic class that is specified in the label on the packet (41).

15. Being described in any claims above, Automatic Classification and Prioritization Software and Wireless Local Area Networking devices that can run this software on, characterized as If the packet to be transferred can not be classified as video packet, it is checked if it can be classified as a voice packet of any kind of voice transmission format based on packet header, content, relation to previous or future packets or any other attribute required by any voice transmission format (34)

16. Being described in any claims above, Automatic Classification and Prioritization Software and Wireless Local Area Networking devices that can run this software on, characterized as if the packet is classified as voice packet, detailed classification of that packet is also done based on

> packet header, content, relation to previous or future packets or any other attribute required by any voice transmission format (35).

17. Being described in any claims above, Automatic Classification and Prioritization Software and Wireless Local Area Networking devices that can run this software on, characterized as if detailed classification is successful, the classified voice packet is labeled as a predetermined traffic class for its type (37) or a traffic class that is created based on the conditions present at that moment (36). 802.11 module (17) transmits the packet with the priority of traffic class that is specifieded in the label on the packet (41).

18. Being described in any claims above, Automatic Classification and Prioritization Software and Wireless Local Area Networking devices that can run this software on, characterized as if the packet to be transferred can not be classified as video or voice packet, it is checked if it can be classified as a specially defined packet based on packet header, content, relation to previous or future packets or any other attribute required by special packet format (38).

19. Being described in any claims above. Automatic Classification and Prioritization Software and Wireless Local Area Networking devices that can run this software on, characterized as if the packet is classified as specially defined packet, it is labeled with its predetermined traffic class (39) and 802.11 module (17) transmits the packet with the priority of traffic class that is specified in the label on the packet (41).

20. Being described in any claims above, Automatic Classification and Prioritization Software and Wireless Local Area Networking devices that can run this software on, characterized as if the packet to be transferred can not be classified as video, voice or special packet, it is labeled

(40) as normal traffic class (20) and transmitted (41) over 802.11 module (17) with 802. lie normal traffic class priority (18) and the priority of this class is the same as unprioritized packets or packets transmitted by ordinary 802.11 devices which do not utilize 802. lie classification and the packets that will be transmitted in this class have the same priority as of packets from other clients in the environment.

21. Being described in any claims above, Automatic Classification and Prioritization Software and Wireless Local Area Networking devices that can run this software on, characterized as the labeled packets to be transmitted are ready for transmission with the priority of their traffic class. These packets are assigned to 802. lie (18) classes (19,20,21,22) based on traffic class values specified in their labels and they are transmitted (41) by 802.11 module (17) according the their priority level.

22. Being described in any claims above, Automatic Classification and Prioritization Software and Wireless Local Area Networking devices that can run this software on, characterized as Automatic Classification and Prioritization Software ends for labeled and transmitted packets (42). Automatic Classification and Prioritization Software is rerun for every packet that is queued to be transmitted over 802.11 module (17)