MULTICHANNEL CLUSTERING ALGORITHM FOR WLAN AND WPAN DEVICES

MULTICHANNEL CLUSTERING ALGORITHM FOR WLAN AND WPAN DEVICES N.Meenakshi 1 1 (M.E Communication Systems, Anna University, Chennai, India, meenu.ece19@gmail.com) Abstract- The wireless local area network (WLAN) and wireless personal area network (WPAN) operates ISM band. Spectrum sharing within the similar network can be established by MAC protocols. In heterogeneous networks, the coexistence between WPAN and WLAN has (e.g., ZigBee and Wi-Fi) a difficult problem. The established MAC protocols are unsuccessful in dealing with the different broadcast-power levels, asynchronous time-slots, and unsuited PHY layers of such varied networks. Moderateto-high Wi-Fi traffic will degrade the performance of synchronized ZigBee. To overcome this problem to introduce a method is called Multichannel Clustering Algorithm(MCA). The Multichannel clustering algorithm has inter cluster channel and intra cluster channel. The Multichannel Clustering Algorithm reduces the collision between WLAN and WPAN devices. The Multichannel Clustering Algorithm will improve throughput and high level interference is also negligible. Keywords 802.11, 802.15.4, coexistence, heterogeneous networks, software MATLAB, Wi-Fi, ZigBee. 1. INTRODUCTION The WLAN and WPAN operate on ISM the band. Allowing spectrum sharing along with these networks will i m p r o v e spectrum utilization. Consider the two networks Wi-Fi (IEEE 802.11 WLAN) and ZigBee (IEEE 802.15.4 WPAN), that operate in the 2.4 GHz. WLAN and WPAN collocated means, ZigBee connection loss will occur during peak hours due to Wi-Fi interference. To avoid the interference is to allocate the ZigBee devices. The CSMA based networks are used to avoid the Interference. But these methods, the performance will degrade in the heterogeneous networks. To resolving the coexistence between Wi-Fi and ZigBee at the heterogeneous networks Multi Channel clustering algorithm is proposed. This project is based on interference detection between Wi-Fi and ZigBee devices by using Multichannel clustering algorithm. The Multi channel clustering algorithm is using multiple channels in a WPAN in the presence of WLAN interference. The algorithm includes interference detection and avoidance schemes to adaptively reconfigure multiple channels in an IEEE 802.15.4 cluster tree network to avoid interference from WLANs. It reduces the collision between Wi-Fi and ZigBee devices. It has ability to reduce or negligible the high level interference between Wireless local area networks (WLANs) and Wireless personal area networks (WPANs). The main objective of this project is to develop the interference detection and reduce the interference between Wi-Fi and ZigBee Devices. Since it is improve performance between Wi-Fi and ZigBee devices. High level interference is also negligible Wireless local area networks (WLANs) and Wireless personal area networks (WPANs). 2. AN OVERVIEW OF PROPOSED MODEL Wireless local area networks (WLANs) based on IEEE 802.11 specifications and Wireless personal area networks (WPANs) based on IEEE 802.15.4 specifications need to coexist in the same Industrial, Science and Medial (ISM) band. In heterogeneous network has coexisting problem between WLAN and WPAN devices. The overall method proposed here is to detect the interference between Wi-Fi and ZigBee devices by using ACK/NACK based interference detection. Then it classifies the intra cluster interference and inter cluster interference. In heterogeneous networks, the coexistence between WPAN and WLAN has (ZigBee and Wi-Fi) a difficult problem. To overcome these problems multichannel clustering algorithm is proposed. The main objective of this project is to develop the interference detection and reduce the interference between Wi-Fi and ZigBee devices. Since it is improve performance between Wi-Fi and ZigBee devices. High level interference is also negligible Wireless local area Volume: 01 Issue: 05 Year 2014 www.ijmtes.com 86

networks (WLANs) and Wireless personal area networks (WPANs). 3. METHODOLOGY The proposed methodology is shown in the Fig. 3.1. ACK/NACK detection Interference classifier Inter cluster Fig.3.1 Interference Detection System 4. MODULE DESCRIPTION The project involves four major modules as listed below. ACK/NACK Detection Interference classifier Channel selection using ACS method Clustered channel hopping using PRSG The modules are described in detail below. A. ACK/NACK Detection Inter cluster Channel selection using ACS method Clustered channel hopping using PRSG The IEEE 802.15.4 WPAN specification describes three topologies: star, peer to peer, and cluster tree topologies. In a PAN, there must be one PAN coordinator (PNC) and it is the primary controller of the PAN. Each independent PAN has a unique identifier, called the PAN id (PID). In the cluster tree topology, devices are grouped by a cluster and a cluster head (CLH), a local coordinator in the cluster, is responsible for managing the cluster and the cluster identifier (CID) is the shared ID number for all devices in the cluster. The cluster tree network is widely used to increase the coverage area of the ZigBee network using a multi cluster structure. A bridge device (BRD) is a node that is directly connected to a cluster head of a neighboring cluster. An ACK/NACK based interference detection scheme does not require redundant procedures for detecting interference. It is the most suitable for clustertree networks. After a sender transmits a frame, it waits for the ACK frame from its recipient. When the sender cannot receive the ACK frame within a timer value, it reports NACK for this transmission. Whenever NACK is reported, it counts up the variable #SuccessiveNACK by 1. When #SuccessiveNACK becomes greater than the threshold ThNACK, the sender finds that it suffers from interference. In a beacon enabled cluster tree network, can use beacon frames to detect interference. The basic concept of the beacon based interference detection scheme is similar to the procedure of ACK/NACK based interference detection scheme. All devices except the CLH and PNC receive beacon frames at the beginning of each super frame. When the number of successive lost beacons is greater than the threshold ThBF, the devices finds that they suffer from interference. For important communication links, such as a link between a CLH and BRD, devices can send and receive test frames regularly to examine the link status more often and reliably. Since all devices in the group use the same frequency channel, they have to detect and avoid the interference in the group at the same time. If only some part of devices in the group detect and avoid the interference by changing their frequency channel, other devices which cannot detect the interference can remain in the previous channel. B. Interference Classifier ZigBee cluster tree has two types: Inter cluster ZigBee Channel Intra cluster ZigBee Channel An intra cluster channel is a channel established by devices in a single cluster and an inter cluster channel is a channel established by a CLH of one cluster and a BRD of another cluster. The same channel group is defined as a group of devices that share the same channel information and use the same channel. Volume: 01 Issue: 05 Year 2014 www.ijmtes.com 87

The channel used within a cluster, called an intra cluster channel, is selected and managed by the cluster head (CLH) of the cluster. The channel used to connect two different clusters, called an inter cluster channel, is selected and managed by the cluster head (CLH) from one cluster and the bridge node (BRD) from another cluster. Interference is avoided by adaptively changing the channel carrier frequency of ZigBee nodes in the presence of WLAN interference. The CLH and BRD, belong to the same channel group. Both of the CLH and BRD, or one of them can experience the interference. Inter cluster channels need to be treated with greater care, compared with intra cluster channels, because the performance may degrade more severely interfered by WLAN APs. For more robustness on the inter cluster channels, CLHs send periodic test frames to their BRDs. The CLH easily detects whether its intercluster channel experiences interference. Fig. 4 Example of a ZigBee Cluster tree Network with Intra and Inter Cluster ZigBee Channels The Intra cluster is the same channel group. A WLAN AP channel provides interference to the ZigBee channel used in the cluster. Three ZigBee devices (Dev1, Dev2, and Dev4) are within the communication coverage of the WLAN AP. Each node, except the CLH, can determine whether it experiences interference by using the ACK/NACK based and Beacon based interference detection schemes at the same time. If the node is a CLH, then it only uses the ACK/NACK based interference detection scheme to detect interference in the cluster. If the node detects the interference, it then sends a Channel Change Broadcast Message (CCBM) frame and obtains the next channel using its PID and CID. Then it waits treconf for reconfiguration. The Inter cluster has CLH and BRD, belong to the same channel group. Both of the CLH and BRD or one of them can experience the interference. Inter cluster channels need to be treated with greater care compared with intra cluster channels, because the performance may degrade more severely if they are interfered by WLAN APs. The CLHs send periodic test frames to their BRDs. The CLH easily detects whether its inter cluster channel experiences interference using the ACK/NACK based interference detection scheme. ACK frames are sent from the BRD corresponding to data frames or test frames sent from the CLH. The BRD can detect the interference using the test frame-based interference detection scheme. After detecting interference, devices send a CCBM frame and obtain the next channel using their PID, CID1 (CID of CLH), and CID2 (CID of BRD). Then it waits treconf for reconfiguration. C. Channel Selection using ACS method The coexistence of the IEEE 802.15.4 and the IEEE 802.11 networks, as well as the channel allocation, can be addressed by assessing the interferences from an AP (Access Point) IEEE 802.11 to an IEEE 802.15.4 network. An adaptive channel allocation method, by means of interference detection and based on a random adaptive channel selection scheme. This channel selection method can be implemented when the RF environment is congested and it is difficult to determine the free channel. The adaptive channel selection (ACS) method that can be integrated in a street lighting monitoring and control system spread across a wide a geographical area of several kilometers, which operates within an environment that is highly disrupted by interferences. The ACS scheme entails that each device in the network should contribute to the optimal selection of the operating channel. Since the network can consist of a large number of nodes, it can be affected by a number of 802.11 access points, leading to a significant decrease in the performance level and thus compromising the entire system. When WLAN interference is detected, the ACS method determines the optimal operation channel. The node that initializes the ACS method is the coordinator. When a node detects the occurrence of interference, it sends an ACS request to the coordinator node. The coordinator depending on the number of nodes that send ACS requests decides when the entire network enters the ACS scanning mode. Volume: 01 Issue: 05 Year 2014 www.ijmtes.com 88

The nodes located at the extremity of the network (at a higher network depth) will have lower priority in terms of the channel selection than those which have a lower network depth, thus implicitly enabling links that are more important for the network operation. The coordinator will select the optimal operating channel which has the lowest value of the calculated weighted average. To create interference between WLAN (IEEE802.11) and WPAN (IEEE802.15.4) channels. When WLAN and WPAN channels transmit the data interference will occur at the Wi-Fi channel and ZigBee channel. If the interference is occur, the transmitted data will not send successful manner. D. Clustered channel hopping using PRSG Once a device detects interference within the same channel Group, it now starts to change its channel to a new channel using a pseudorandom based interference avoidance scheme. To evaluate the availability of the next channel Energy Detection (ED) scans can be used. If the return value of the ED scan on the next channel shows that the next channel is not used temporarily, then the node is aware that changing channel would be successful. When the return value of the ED scan shows that the next channel is busy, the node can increase the counter by one and obtains another channel from the PRSG. 5. RESULTS AND DISCUSSION The proposed method is tested, to create the interference between Wi-Fi and ZigBee. In this method first create random nodes in the Wi-Fi and ZigBee. Then allocate the distance in Wi-Fi and ZigBee nodes. Then create interference between Wi-Fi and ZigBee nodes. To allocate channel for Wi-Fi and ZigBee in Fig.5.1 Wi-Fi (IEEE802.11) has channel 1 to channel 13 and ZigBee (IEEE802.15.4) has channel 11 to channel 26. The frequency is denoted as MHZ. overlapping and non overlapping channels are denoted in Fig.5.1 Fig. 5.1 Allocate the channel between Wi-Fi and ZigBee From fig 5.1 Green colors indicate Wi-Fi non overlapping channels and blue color is ZigBee channels. Dot line indicates Wi-Fi overlapping channels. One Wi- Fi channel is equal to four ZigBee channels. Fig. 5.2 Wi-Fi and ZigBee Location Then allocate the location of Wi-Fi and ZigBee nodes. It is shown in fig 5.2. From this figure there are two Wi-Fi networks and twenty ZigBee nodes. Red color curve indicates coverage area of the Wi-Fi Networks and blue color dotted line indicates ZigBee nodes. From this Fig X and Y axis both are Area in meter. Then identify the transmitting nodes and receiving nodes. It is shown figure 4.3. This simulation has 10 rounds of transmitting and receiving nodes. Fig. 5.3 Example for transmitting and receiving nodes This Fig shows example for one round of transmitting and receiving nodes. The Red color node indicates the transmitting node. The blue color node is receiving node. In this Fig node11 is transmitter node and node 13 is receiver node. The 4 th node is header node. Fig 5.4 shows inter cluster ZigBee channels. The channel used to connect two different clusters, called an inter cluster channel, is selected and managed by the cluster head (CLH) and BRD node. The CLH easily detects whether its inter cluster channel experiences interference using the ACK/NACK based interference detection scheme. Fig 5.4 shows transmitting node has one cluster network and receiving node has another cluster network. Volume: 01 Issue: 05 Year 2014 www.ijmtes.com 89

Channel 5 has cluster header node and transmitting node. Channel 1 has receiving nodes. From fig 5.4 red color node that is, node 1 is transmitting node and blue color node that is, node 17 is receiving node. From this figure communication take place between different cluster networks. cluster networks. Communication takes place one cluster to another cluster. In this figure node 8 is header node. The multichannel channel cluster network will take several rounds. Each round has different header node, transmitting node and receiving node. From figure 4.7 green color node that is, node 8 is header node. Red color node that is node 6 is transmitting node and blue color node that is node 10 is receiving node. Red color square box is Wi-Fi network. Fig. 5.4 Inter cluster ZigBee channels Fig. 5.7 Packet loss rate Fig. 5.5 Intra cluster ZigBee channels From fig 5.7 shows packet loss rate. In this figure Cooperative carrier signaling mechanism (CCS) is previous method by using reduce interference between Wi-Fi and ZigBee. No CCS is interference. Fig 5.5 shows intra cluster ZigBee channels. An intra cluster channel is a channel established by devices in a single cluster, is selected and managed by the cluster head (CLH). Fig. 5.8 Packet delivery delay Fig. 5.6 Multi Channel Cluster Networks Especially wireless local area networks (WLANs) based on IEEE 802.11 specifications and wireless personal area networks (WPANs) based on IEEE 802.15.4 specifications need to coexist in the same Industrial, Science and Medial (ISM) band. Fig 5.7 shows Multi Channel cluster networks. Available frequency spectrum is split into multiple channels. In Multichannel wireless network communications, the channel is divided into a control channel and multiple data channels. This figure has five Fig. 5.9 Percentage of back off failures Volume: 01 Issue: 05 Year 2014 www.ijmtes.com 90

[4] Junaid Ansari, Tobias Ang and Petri Mahonen, Fast and Reliable Detection of Wi-Fi Networks Using IEEE 802.15.4 Radios IEEE Trans. 2003. [5] R. Gummadi, H. Balakrishnan, and S. Seshan, Metronome:Coordinating spectrum sharing in heterogeneous wireless networks, in Proc. 1st COMSNETS, 2009. Fig. 5.10 Beacon signal [6] Z. J. Haas and J. Deng, Dual busy tone multiple access (DBTMA) A multiple access control scheme for ad hoc networks, IEEE Trans.Jun. 2002. [7] Ramakrishna Gummadi, Hari, Coordinating Spectrum Sharing in Heterogeneous Wireless Networks, IEEE Trans.2011. [8] Ruitao Xu, Gaotao Shi, Multichannel ZigBee networks for avoiding WiFi interference,ieee Trans.2011. Fig. 5.10 Loss rate due to Wi-Fi preemption between Wi-Fi traffic rate and ZigBee ACK loss rate 6. CONCLUSION The wireless local area network (WLAN) and wireless personal area network (WPAN) operates ISM band. Spectrum sharing within the similar network can be established by MAC protocols. In heterogeneous networks, the coexistence between WPAN and WLAN has (e.g., ZigBee and Wi-Fi) a difficult problem. Multichannel clustering algorithm is reducing the collision between Wi-Fi and ZigBee devices. High level interference is also negligible. REFERENCES [1] Xinyu Zhang and Kang G. Shin, Fellow, Cooperative Carrier Signaling: Harmonizing Coexisting WPAN and WLAN Devices, IEEE Trans.2013. [2] J.Haas, Jing Deng, Multiple Access Control Scheme for Ad-hoc Networks, IEEE Trans.2002. [3] M.Petrova, L.Wu, P.Mahonen, and J. Riihijarvi, Interference measurement on performance degradation between colocated IEEE802.11g/n and IEEE 802.15.4 networks, IEEE Trans.2007. [9] A. Lavric, V. Popa, Adaptive channel selection algorithm for a large scale lighting control ZigBee network, IEEE Trans.2012. [10] Joon-Ho Lee, Seok Le, Predictive channel scanning and switching algorithm for the coexistence of IEEE 802.15.4 and WiFi, IEEE Trans.2012. [11] C.-J.M. Liang, N. B. Priyantha, J. Liu, and A. Terzis, SurvivingWi-Fi interference in low power ZigBee networks, in Proc. ACM SenSys,2010. [12] R. Gummadi, H. Balakrishnan, and S. Seshan, Metronome: Coordinating spectrum sharing in heterogeneous wireless networks, in Proc.1st COMSNETS, 2009. [13] S. Pollin, I. Tan, B. Hodge, C. Chun, and A. Bahai, Harmful coexistence between 802.15.4 and 802.11: A measurement-based study, in Proc. CrownCom, 2008. [14] J.-H. Hauer,V.Handziski, and A.Wolisz, Experimental study of the impact of WLAN interference on IEEE 802.15.4 body area networks, in Proc. EWSN, 2009. [15] Zygmunt J. Haas, Jing Deng, Dual Busy Tone Multiple Access- A Multiple Access Control Scheme for Ad Hoc Networks IEEE Trans.2002. [16] Junaid Ansari, Tobias Ang and Petri Mahonen, Fast and Reliable Detection of Wi-Fi Networks Using IEEE 802.15.4 Radios IEEE Trans.2009. Volume: 01 Issue: 05 Year 2014 www.ijmtes.com 91