WO2009154581A1

WO2009154581A1 - Wireless local area networking devices providing protection for high priority packets

Info

Publication number: WO2009154581A1
Application number: PCT/TR2008/000076
Authority: WO
Inventors: Metin Ismail Taskin; Tolga Kurt; Firat Birlik
Original assignee: Airties Kablosuz Iletisim Sanayi Ve Dis Ticaret As
Priority date: 2008-06-19
Filing date: 2008-06-19
Publication date: 2009-12-23
Also published as: TR201010642T1

Abstract

This invention is related to increasing the Quality of Service (QoS) and lowering Packet Loss Rate (PLR) by protecting high priority packets transmitted in a WLAN from hidden nodes that is often encountered in neighboring WLANs and 802.11s mesh networks by utilizing selective RTS/CTS signaling architecture. The WLAN devices developed in this invention send RTS signal and wait for CTS before sending high priority packets but do not send RTS for other packets which are lower priority. High priority packets are usually video or voice packets that require real time delivery with high QoS requirements and with very low PLR. By enabling RTS/CTS signaling only for high priority traffic, the total overhead caused by RTS/CTS signaling is minimized and the total network throughput capacity is optimized. Those devices can also transfer voice and video or like signals at high quality by forming IEEE 802.11s Standard compliant wireless mesh networks in order to overcome wireless signal attenuation problems encountered in concrete buildings. Every mesh point in 802.11s mesh network also implement selective RTS/CTS signaling in order to protect high priority packets throughout the mesh network. The devices invented may also include VoIP, IPTV or DSL modem features integrated in the same hardware utilizing different IEEE 802.11 standards including IEEE 802. Hg and IEEE 802.Hn.

Description

WIRELESS LOCAL AREA NETWORKING DEVICES PROVIDING PROTECTION FOR HIGH PRIORITY PACKETS

SUBJECT OF THE INVENTION

This invention is related to Wireless Local Area Networking (WLAN) devices with high priority packet protection algorithm that increase the Quality of Service (QoS) and lower Packet Loss Rate (PLR) by protecting high priority packets transmitted in a WLAN from hidden nodes, that are often encountered in neighboring WLANs and 802.11s mesh networks by utilizing selective Request to Send (RTS)/Clear to Send (CTS) signaling architecture. The WLAN devices with high priority packet protection algorithm developed in this invention send RTS signal and wait for CTS before sending high priority packets but do not send RTS for other packets which are lower priority. High priority packets are usually video or voice packets that require real time delivery with high QoS requirements and with very low PLR. By enabling RTS/CTS signaling only for high priority traffic, the total overhead caused by RTS/CTS signaling is minimized and the total network throughput capacity is optimized. Those devices can also transfer voice and video or like signals at high quality by forming IEEE 802.11s Standard compliant wireless mesh networks in order to overcome wireless signal attenuation problems encountered in concrete buildings. Every mesh point in 802.11s mesh network also implements selective RTS/CTS signaling in order to protect high priority packets throughout the mesh network. The devices invented may also include VoIP, IPTV or DSL modem features integrated in the same hardware utilizing different IEEE 802.11 standards including IEEE 802. Hg and IEEE 802. Hn.

THE OBJECTIVES OF THE INVENTION

The objectives of Packet Content based RTS/ CTS implementation on Wireless Local Area Networking devices that run this software developed in this invention:

• Transfer video data over Wireless Local Area Networks (WLANs), in particular for networks with mesh topology, with high quality.

• Minimize the re-transmissions by avoiding collisions because of hidden nodes, therefore providing lower packet loss rate, jitter and latency.

• Applying the RTS/CTS method exclusively to high priority packet transmissions, therefore reducing the overhead that would exist if applied to all data packets. • Applying the RTS/CTS architecture specific to high priority traffic when protecting against the neighboring WLAN hidden nodes

• Applying the afore-mentioned protection mechanism to all hops in a mesh network so that the high priority transmission is protected through all the mesh nodes.

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 6-10 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 802.11b supports HMbps as the highest physical transmission rate while 802.11b 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. 802. Hn supports 300 Mbps to 600 Mbps physical data rates with actual data throughput in the order of several hundred Mbps.

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 the afore-mentioned 802.11 standards, medium access control layer only differs by several predefined values. 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, it has a better chance to win the contention and to start transmission. Four different traffic classes with varying priorities are defined in 802.He with different CW values. These traffic classes are from lowest priority to highest priority as follows: Background (BG), Best Effort (BE), Video (Vl) and Voice (VO).

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 an access category is very high, it is possible that resources left to the high priority client is not enough due to additional delay, jitter and packet loss caused by collisions with packets transmitted by hidden nodes that are often encountered in multiple neighboring wireless networks. Especially in wireless mesh networks, a packet is transmitted over several nodes till it reaches the final destination; so the possibility of hidden nodes is much bigger and end-to-end delay and end-to- end throughput will be greatly affected by collisions at mesh nodes compared to a single transmission.

As mentioned above, the efficient classification of this traffic with respect to priority is also one of the issues in WLANs. Recently, we have filed Automatic Classification and Prioritization

Algorithm described in the applied patent: TPE:2007:5158, "Wireless Local Area Networking Devices providing Quality of Service Based on packet content transmitted over local area networks", for methodologies and devices accomplishing this task.

Wireless Distribution System (WDS) is an 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.

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. IEEE 802. Hn standard proposes data rates that can reach well above lOOMbps, which will enable further video-based multi-media applications. However, with concrete walls attenuating radio signals and large houses the data rates degrade rapidly, usually the transmission between the source and destination typically requires multi-hop mesh networks in order to achieve higher network throughput. 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.

One particular example for high priority downlink transmission is Internet protocol television (IPTV) applications as given in Figure 5. IPTV provides television services by utilizing an underlying IP network architecture. Unlike the data traffic, the video traffic through the downlink direction is continuous rather than bursty, and more jitter and latency sensitive. Hence, the IPTV streams are considered higher priority traffic compared to data traffic.

. One of the main sources of interference is collision due to hidden nodes. A hidden node problem can occur (as shown in Figure 4), when a node (30) is transmitting to a destination (30a) in the same WLAN and at the same time other nodes (31 or 32) which cannot receive the aforementioned transfer but can reach to the destinations receiver and causes a collision. A Request to Send (RTS)/ Clear to Send (CTS) methodology can be utilized to eliminate the above-mentioned effect. The node (30) that wants to transmit a data packet to the destination (30a) sends an RTS signal which may not be heard by hidden nodes (31, 32) but the destination node (30a) sends a CTS signal as a response to RTS and CTS signal is heard by all the hidden nodes (31,32) that the destination node can hear from. The hidden nodes (31, 32) that receive the CTS signal from the destination node do not transmit until the packet transmission from originating node (30). The RTS/CJS procedure is invoked optionally. As a channel reservation mechanism, the RTS/CTS exchange is efficient only for longer frames because of the extra overhead involved. Therefore, typically RTS/CTS is triggered for activation when a certain packet size is exceeded.

The effect of hidden nodes is more severe in mesh networks compared to the effect in the case of neighboring networks. Potential collisions may occur each and every hop from source to destination and the overhead may further increase. Additionally, issues related to virtual blocking can further add to the overhead. If the mesh network given in Figure 5 is considered, where there is a transmission originated from the IPTV video source (33) through internet (34) and gateway (35) aimed at the receiver of the set top box of the IPTV (51), there can be another node transmitting (50) low priority data in the same mesh architecture but in the opposite direction. This may result in a collision occurring at any node on the mesh network (35,40,48) since (35) and (52) cannot utilize the carrier sensing architecture due to either distance or any other factor obstructing the transmission.

When it is triggered active, the source sends an RTS frame. Hidden node may hear this request as well. RTS frame should also contain the duration of the reserve period. The NAV is set by all stations detecting the RTS frame. Nodes other than the destination set the NAV at this value and do not transmit until the duration expires. After receiving the request, the destination node transmits a CTS frame. The CTS also contains information on the duration. The station within the interfering range will likely receive the CTS, even if they did not receive the RTS and update their NAV. The NAV provides protection through the ACK. The NAV serves as a ^'virtual^* carrier sense mechanism. As a result, collision protection is achieved from the hidden nodes.

The corresponding MAC layer architecture is detailed in Figure 6. Once the transmitting node (53) transmits RTS, the receiver of RTS (54) sets the NAV RTS (61), waits for the short inter- frame space (63) and transmits CTS (58). Upon the completion of CTS transmission, NAV CTS is set (62). All the nodes in the network, who receive CTS transmission (other than 53), go into silent mode until the beginning of the new contention window. After another SIFS, the data/video transmission is accomplished (59) in the reserved access medium (65). Upon the completion of the transmission, a DCF inter-frame space expires (64). Finally contention window starts again (66).

Even though the collision protection is provided, the expense of the methodology is however increased overhead in the system which results in reduction in the net throughput. In order to avoid the overhead introduced to a certain level, a threshold of packet size is utilized. If a packet has a larger size than the threshold, the CTS/RTS is activated.

There are various types of traffic going through the WLAN system with different contentions and priorities. Prior art concentrates heavily on differentiating between different types of traffic and assigning transmission priorities accordingly. One example of these techniques is called Tiered contention multiple access (TCMA). Each station can determine if the transmitted packets are voice or video or other data and their corresponding QoS. The methodology schedules different type of traffic depending on their QoS requirements. However, even though traffic with higher QoS requirements is transmitted with high priority, this still does not reduce the collision probability in the system. The QoS for video becomes more important particularly due to the use of point coordination function (PCF) instead of distributed coordination function

(DCF) enabling a single path between transmitting nodes and receiving node. The problem with the transmission of video and RTS/CTS architecture is that typically packet size of the video transmissions is shorter than the regular data transmissions. Once, the threshold for RTS/CTS is activated, only the packets longer than the threshold utilize RTS/CTS and since the video packets are shorter, utilizing RTS/CTS for them means utilizing them for almost all transmissions.

In order to protect the video transmission, one solution that exists in the literature is referred as CTS-to-self. When a node wants to reserve the transmission time, it can transmit a CTS message with its own address. This will reserve the channel for the transmission for the specified period. However, if the interfering transmitter cannot receive the CTS message, this methodology will not help the collision as in the case of hidden terminals.

When a collision occurs for low priority data traffic, re-transmissions may be acceptable. However, when video or voice packets are transmitted, any retransmission may cause a delay in the received packets. This results in unacceptable video or voice quality due to latency and jitter requirements of the real-time traffic. Also, video packets are usually streamed continuously and therefore it is quite likely that a single collision will be followed by a series of collisions. Unlike the previous art, in this invention RTS/CTS system is applied specifically to video streams. This is an opposite of the traditional methodology where longer packets are used in conjunction with RTS/CTS. By utilizing the RTS/CTS exclusively to video enables a higher QoS for video transmissions without the larger overhead of applying QoS to all systems.

DESCRIPTON OF THE FIGURES AND THE COMPONENTS

The figures provided here further explain video transmission specific RTS/CTS architecture.

Figure 1 -An example usage scenario

Figure 2 -An example block diagram of a device utilizing Wireless Local Area Networking

Devices Providing Protection for High Priority Packets and having capability of forming mesh networks

Figure 3 -Flow diagram of algorithm

Figure 4 - Hidden Node Problem in neighboring networks

Figure 5 - Hidden node problem in mesh networks

Figure 6 - Analysis of overhead in MAC layer due to RTS/CTS

The description of each component in the figures is below:

I. 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 weakened 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)

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

13. Digital video server (Video provider)

14. VoIP server (Voice communication provider)

15. Network Layer 16. Mesh system

17. Identification and Prioritization module

18. IEEE 802.11 system

19. Ethernet system

20. IEEE 802.11 radio system 21. Connection to cable network

22. Transceiver antennae

23. Traffic classification with respect to IEEE 802. lie classes

24. Background traffic

25. Best effort traffic 26. Voice traffic

27. Video traffic

28. Request to send

29. Clear to send

30. Transmitting AP 30a. Receiving node

31. Hidden node -2

32. Hidden node -1

33. Source of video transmission in the mesh network. 34. Broadband Network.

35. Wireless Gateway

36. RTS

37. CTS 38. High priority packets such as video

39. Low priority packets

40. First hop in the mesh network

41. RTS

42. CTS 43. High priority packets such as video

44. Low priority packets

45. CTS

46. Low priority packets

47. High priority packets 48. Second hop in the mesh network.

49. RTS

50. CTS

51. IPTV and set-top box

52. Node transmitting in the opposite direction of video traffic 53. Transmitter

54. Receiver

55. Network allocation vector

56. Total overhead time in the transmission due to RTS and CTS signaling 57. RTS

58. CTS

59. Data transmission

60. Acknowledgement for reception of the data 61. Setting of network allocation vector by RTS

62. Setting of network allocation vector for CTS

63. Short Inter-frame space

64. DCF lnterframe space

65. Time reserved for transmission of node 34. 66. Access with contention

DETAILED DESCRIPTION OF THE INVENTION

In this invention, Wireless Local Area Networking (WLAN) devices with high priority packet protection algorithm providing better Quality of Service (QoS) and lower Packet Loss Rate (PLR) for high priority traffic by protecting high priority packets from collisions, that may be caused by hidden nodes that are usually encountered in WLAN networks, are designed. The WLAN devices with high priority packet protection algorithm in this invention sends RTS packets exclusively for high priority packets and ordinary traffic is transmitted without using RTS/CTS signaling. That way the total overhead caused by RTS/CTS signaling is minimized. The devices in this invention may also have VoIP, IPTV and DSL modem features integrated.

The WLAN devices with high priority packet protection algorithm developed 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. They act as mesh points and each mesh point enables selective RTS/CTS signaling exclusively for high priority traffic. That way selective RTS/CTS signaling is applied throughout the mesh network until the packet is delivered to its destination.

In one embodiment the WLAN devices with high priority packet protection algorithm provide better Quality of Service and lower Packet loss rate for high priority traffic is the hidden node problem in neighboring networks as shown in Figure 4. When the WLAN devices with high priority packet protection algorithm (30) transmitting high priority traffic in the downlink (30), such as IPTV packets, transmits an RTS signal. Upon receiving the RTS, the terminal (30a) transmits a CTS signal. The hidden nodes (31, 32) in the neighboring networks that cannot reach the node at (30) and cannot receive RTS, receives the CTS and pauses their transmission. Their silencing for the period mentioned in RTS/CTS structure enables the high priority traffic to pass without collisions from the hidden nodes. For low priority traffic passing through (30), RTS/CTS signaling is not used.

In one embodiment the WLAN devices with high priority packet protection algorithm is used to prevent the collisions in wireless mesh networks by employing the RTS/CTS architecture at every node starting from the wireless gateway (35) which is one of the WLAN devices with high priority packet protection algorithm. Upon the reception of high priority traffic by the wireless gateway (35), RTS (36) is transmitted. Upon the reception of RTS (36), first node (40), which is also the WLAN devices with high priority packet protection algorithm, transmits the CTS (37) and the medium is reserved for the transmission of high priority traffic (38). Low priority traffic (39) waits for the duration given in the CTS (37). When first node (40) receives the transmission, since the packet is high priority, it will also transmit an RTS (41) and the second hop (45) receiving this RTS (41) will transmit a CTS (42). Upon receiving CTS (42), the node (52) which needs to transmit the low priority packets (46) will be silenced for the duration given in the CTS (42). If there are more nodes which are one of the WLAN devices with high priority packet protection algorithm that the high priority packets need to pass through, the same RTS/CTS and high priority packet transmission sequence is repeated for every transmission until the high priority packet reaches its destination (51).

Generally high priority packets are Voice and video packets where low priority packets may be data packets and general internet traffic.

In one embodiment in the WLAN devices with high priority packet protection algorithm, initially, the content of the packet is classified in the system as either high priority or low priority. High priority packets may be voice or video packets, low priority packets may be data or background packets. The packet classification can achieved by Automatic Classification and Prioritization Algorithm described in the applied patent: TPE:2007:5158, "Wireless Local Area Networking Devices providing Quality of Service Based on packet content transmitted over local area networks".

Other than the afore-mentioned method, the packet prioritization can be also achieved by other methodologies. When the packet is identified to be high priority it is labeled as high priority packet and put into 802. lie high priority queue (23). High priority queues in 802. lie are Video (Vl) (26) and Voice (VO) (27), low priority queues are Background (BG) (24), Best Effort (BE)

(25) queues. This decision mechanism is included in the WLAN architecture as shown in Figure 2.

In one embodiment in the WLAN devices with high priority packet protection algorithm, the selection of the packets that will utilize the RTS/CTS signaling can be made according to a criteria which is a combination of transmission length and priority, which can be applying RTS/CTS to high priority packets which are longer than a certain transmission duration.

The WLAN devices with high priority packet protection algorithm also optimize the network throughput by reducing the total overhead of RTS/CTS signaling by sending RTS signals just for high priority packets and do not send RTS signals for low priority packets. As an example, consider the transmission of video traffic over WLAN network such as IEEE 802. Hn occupying 10% of the network traffic capacity. The MAC layer signaling is provided in Figure 5. The total overhead is the duration of RTS and CTS and two SIFS periods. Although it depends on the specific modulation used in the PHY layer, this may result in an overhead about 23.5%. If all the transmitted data utilizes the RTS/CTS structure, the net throughput reduces about 20%. However, if only video transmission utilizes RTS/CTS, the throughput reduces only about 2%. Therefore, the high priority transmission can be achieved more reliability with much less degradation in the net throughput.

The protection provided by the RTS/CTS mechanism can be achieved in two different situations. First, in a mesh network, all the nodes in the transmission path will be transmitting an RTS, if they receive a high priority traffic packet and the RTS/CTS will provide protection along the entire mesh transmission. Second, when there is an interfering neighbor network, the RTS/CTS will be used to silence the neighbor network for a given transmission duration provided in the RTS content.

Claims

1. Wireless Local Area Networking (WLAN) devices with high priority packet protection algorithm providing better Quality of Service (QoS) and lower Packet Loss Rate (PLR) for high priority traffic by protecting high priority packets from collisions, that may be caused by hidden nodes that are usually encountered in WLAN networks.

2. Being described in any claims above and Wireless Local Area Networking (WLAN) devices with high priority packet protection algorithm characterized as sending RTS packets exclusively for high priority packets and transmitting ordinary traffic without using RTS/CTS signaling, that way minimizing the total overhead caused by RTS/CTS signaling.

3. Being described in any claims above and Wireless Local Area Networking (WLAN) devices with high priority packet protection algorithm characterized as in another embodiment having VoIP, IPTV and DSL modem features integrated.

4. Being described in any claims above and Wireless Local Area Networking (WLAN) devices with high priority packet protection algorithm characterized as, also overcoming radio signal attenuation and wireless coverage problems caused by thick walls by forming

802.11s standard compliant wireless mesh networks and acting as mesh points and each mesh point enables selective RTS/CTS signaling exclusively for high priority traffic. That way selective RTS/CTS signaling is being applied throughout the mesh network until the packet is delivered to its destination.

5. Being described in any claims above and Wireless Local Area Networking (WLAN) devices with high priority packet protection algorithm characterized as: in one embodiment the WLAN devices with high priority packet protection algorithm providing better Quality of Service and lower Packet loss rate for high priority traffic with the hidden node problem in neighboring networks, when transmitting high priority traffic in the downlink (30), such as IPTV packets, transmiting an RTS signal and upon receiving the RTS, the terminal (30a) transmitting a CTS signal and the hidden nodes (31, 32) in the neighboring networks that cannot reach the node at (30) and cannot receive RTS, receiving the CTS and pausing their transmission and their silencing for the period mentioned in RTS/CTS structure enabling the high priority traffic to pass without collisions from the hidden nodes and for low priority traffic passing through (30), not using an RTS/CTS signaling.

6. Being described in any claims above and Wireless Local Area Networking (WLAN) devices with high priority packet protection algorithm characterized as: in one embodiment the WLAN devices with high priority packet protection algorithm being used to prevent the collisions in wireless mesh networks by employing the RTS/CTS architect at every node starting from the wireless gateway (35) which is being one of the WLAN devices with high priority packet protection algorithm.

7. Being described in claim 6 above and Wireless Local Area Networking (WLAN) devices with high priority packet protection algorithm characterized as upon the reception of high priority traffic by the wireless gateway (35), RTS (36) is being transmitted, upon the reception of RTS (36), first node (40), which is also the WLAN device with high priority packet protection algorithm, transmitting the CTS (37) and the medium is being reserved for the transmission of high priority traffic (38), low priority traffic (39) waiting for the duration given in the CTS (37), when first node (40) receiving the transmission, since the packet is high priority, it is also transmitting an RTS (41) and the second hop (45) receiving this RTS (41) and transmitting a CTS (42). Upon receiving CTS (42), the node (52) which needs to transmit the low priority packets (44) being silenced for the duration given in the CTS (42).

8. Being described in claim 6 and 7 above and Wireless Local Area Networking (WLAN) devices with high priority packet protection algorithm characterized as If there are more nodes which are one of the WLAN devices with high priority packet protection algorithm that the high priority packets need to pass through, the same RTS/CTS and high priority packet transmission sequence being repeated for every transmission until the high priority packet reaches its destination (51).

9. Being described in any claims above and Wireless Local Area Networking (WLAN) devices with high priority packet protection algorithm characterized as generally high priority packets being voice and video packets where low priority packets may be data packets and general internet traffic.

10. Being described in any claims above and Wireless Local Area Networking (WLAN) devices with high priority packet protection algorithm characterized as in one embodiment in the WLAN devices with high priority packet protection algorithm, initially, the content of the packet being classified in the system as either high priority or low priority and high priority packets being voice or video packets, low priority packets being data or background packets and the packet classification being achieved by Automatic Classification and Prioritization Algorithm described in the applied patent: TPE:2007:5158, "Wireless Local Area Networking Devices providing Quality of Service Based on packet content transmitted over local area networks".

11. Being described in any claims above and Wireless Local Area Networking (WLAN) devices with high priority packet protection algorithm characterized as other than the afore- mentioned method in claim 9, the packet prioritization being also achieved by other methodologies when the packet being identified to be high priority it being labeled as high priority packet and put into 802. lie high priority queue (23) and high priority queues in 802. lie being Video (Vl) (26) and Voice (VO) (27), low priority queues are Background (BG) (24), Best Effort (BE) (25) queues and the decision mechanism being included in the WLAN architecture as shown in Figure 2.

12. Being described in any claims above and Wireless Local Area Networking (WLAN) devices with high priority packet protection algorithm characterized as in one embodiment in the WLAN devices with high priority packet protection algorithm, the selection of the packets that will utilize the RTS/CTS signaling being made according to a criteria which is a combination of transmission length and priority, which is being applied RTS/CTS to high priority packets which are longer than a certain transmission duration.