Connecting To Several Access Points Simultaneously In IEEE Networks Students: Nadav Dawidowicz, Dvori Yossi Instructors: Dr. Omer Gurewitz Dr. Yehuda Ben Shimol Mr. Itzik Kitroser

Contents Background Motivation Project goal Possible solutions The Platform The selected solution Results Future Work

Introduction The IEEE is a wireless technology based on random access Providing connectivity between wireless stations and wired networking infrastructures Enable stations to travel to various places and still have access to the network

Standards Mbps, S-Band ISM, FHSS b - 11 Mbps, S-Band ISM,DSSS a - 54 Mbps, C-Band ISM, OFDM g - 54 Mbps, S-Band ISM, OFDM n – 600 Mbps, S/C – Band ISM, OFDM

Current Behavior Station Connects to a Single AP ◦Power inefficiency ◦No roaming while connected ◦Break before make

The project goals: Allow connection to several APs ◦green transmission (power efficiency) ◦Reduce the amount of retransmissions ◦Extend the coverage of the network ◦Reduce the amount of handovers

General Architecture

Possible Solutions

A. Creating Several Virtual WNICs ApplicationManager MadWIFI Virtual WNIC #1 Physical WNIC Requirements: The driver should support multiple station instances Routing is controlled by the server application

B. Working As AP In WDS Mode Requirements: The topology should be known from advance The driver should support WDS mode

C. Duplicating the APs

Requirements: Duplicating the MAC address Open network

The Platform - Hardware WNIC based on Atheros 5213 chipset Intel Atom CPU on low power pc platform Trendnet 7dBi antennas 160GB hard drive

Software And Tools OpenSuse MadWifi Wireshark Macchanger Iperf

The MadWifi Project “Multiband Atheros Driver for Wireless Fidelity” MADWIFI is a driver for WNIC Open source Linux driver Configurable and flexible Version MadWifi 0.9.4

The Selected Solution A. Creating Several Virtual WNICs ◦MADWIFI does not support multiple station instances (IOCTL error) B. Working as AP in WDS Mode ◦Known topology – limited mobility C. Duplicating the APs

The Selected Architecture : Duplicated APs. The following parameters should be identical in the wireless interface : MAC address ESSID Channel

The Selected Architecture : Duplicated APs. The APs is composed of: Wireless NIC NIC Bridge between both of them

The AP Duplicate Script macchanger –m 00:25:86:ce:ac:6b wifi0 iwconfig ath0 essid “project” chan 6 Wlanconfig ath0 create wlandev wifi0 wlanmode ap

The Network Diagram

Results Outdoor Measurements APs

Results Outdoor Measurements

Results Indoor Measurements

Summary The goal to connect to several APs was achieved. The improvements: Power efficiency increased Extended AP coverage Less retransmissions But… Network overloading The improvements are case specific

Future Work Finalizing the client server application to measure properly the improvements