Performance Analysis of D2D Based WiFi Offloading for 5G Cellular Network

Abstract

Cellular traffics are increased from time to time.This traffic increase will be difficult for the cellular network to handle everything on its own. To handle this traffic 5G uses millimeter wave technology which have frequency range 30Ghz- 300Ghz.But there is a problem with this millimeter wave in using it in 5G is that waves at these wavelength(1-10mm) gets easily attenuated by the surrounding and they cannot penetrate from a thick wall as well. Configuration of many small cells may solve this problem, which is expensive. This work studies a routing scheme for offloaded 5G cellular data where the data at a user’s telephone set will be first collect in WiFi queue to offload over WiFi and if the WiFi connection is inactive in the user’s telephone set then the data will wait in the queue for a given deadline and while it waits in the WiFi queue, the user’s telephone set will try to set up a device to device (D2D) connection with a neighboring telephone set with an active WiFi connection. When the deadline will reach for the data in the WiFi queue, the user data will be directed to the neighboring telephone set which has an active WiFi connection and which will permit the user’s data to be offloaded through it, else, if no telephone set with an active WiFi connection is found in the environment, after the deadline the data will be sent to the BTS through several small cells. This routing technique increases the probability of getting the wifi server for the user. The Matlab simulation shows transmission delay can be reduced by increasing the deadline rate and also it shows for the same time interval D2D (situation 2)offloading has better utilization factor from delayed wifi offloading (situation 1) and D2D offloading has less average queue length than a WiFi offloading. This shows that D2D offloading has better transmission rate. The result analyzes the effect of increasing number of servers on utilization factor. The simulation result shows that D2D based wifi offloading is 20% more efficient than delayed wifi offloading interms of utilization factor.