Distributed Dynamic Channel Allocation in Wireless Network Channel

Distributed Dynamic Channel Allocation in Wireless Network

Channel Allocation • Cellular network consists of cells. • Mobile service station (MSS) is incharge of a cell. • MSS makes all decision for channel allocation.

MSS Time stamped Request Neighbour MSS • Message passing between MSS & its neighbors to avoid co-channel interference. • Time stamped requests are sent by MSS to neighboring MSS for channel allocation.

Message Types REQUEST RESPONSE MSS CHANGE_MODE RELEASE ACQUISITION Neighborin g MSS

Message Types • REQUEST- requesting to acquire a channel. • RESPONSE- responding to the request from receiving node. • CHANGE_MODE- mode changed from local to borrowing or vice versa. • RELEASE- sending node has released the channel. • ACQUISITION- sending node has acquired a channel.

Implementation

Network Class • Nodes: Arraylist of all nodes/MSS. • Spectrum: Set of all channels

Node Class • PR: set of primary channels. • Use: set of currently used channels • Iuse: Set of channel used by interfering node • Mode: represents mode of the node i. e. Local or borrowing. • Waiting: number of requests not received ACK. • Pending: check if any pending request. • Rounds: number of attempts to acquire channel in borrowing mode.

Public class Node extends Thread { Public Node () { Super(); } Public void run () { Node. request_channel(time); } } Public class Mobile. Host { public static void main(String[] args) { new Node(“MH 1”). start(); new Node(“MH 2”). start(); } }

Concurrency 1. Multiple requests when node in local mode. MH 1. Node 1. request_channel || MH 2. Node 1. request_channel • All requests are proceeded in parallel with no deadlock.

2. Multiple requests when node in borrowing mode. MH 1. Node 1. request_channel (r_Node 2) || MH 2. Node 1. request_channel (r_Node 2) • Algorithm prioritize the request based on time stamps. i. e. Lower the timestamp higher the priority. • Thus no need to apply external locks or synchronize methods.

Plan • Implementing all the messages passed between nodes in java. • Verify the behaviour in case of concurrency.

Thank You Questions ?