Frequency diversity aware wi-fi using ofdm-based bloom filters
- 1. Frequency Diversity-Aware Wi-Fi Using OFDM-Based Bloom Filters Abstract: With the increasing move towards wide band operation in recent Wi-Fi networks, the frequency diversity awareness has become critical for throughput optimization. To exploit frequency diversity in Wi-Fi channels, the access point should measure the channel quality and coordinate the channel contention for all the stations. However, there is a tradeoff between achieving the frequency diversity gain and sustaining protocol efficiency because the channel estimation and coordination consume time and frequency resource that ideally should be used for data transfer. In this paper, we present Diversity-aware Wi-Fi (D-Fi), a novel PHY/MAC protocol, that efficiently exploits frequency diversity. In particular, D-Fi leverages an OFDM-based Bloom filter that synergistically integrates two operations: (i) the channel quality estimation and (ii) the contention based channel allocation. D-Fi also employs a machine learning (ML) method to resolve the false-positive ambiguity caused by the Bloom filter. Furthermore, we develop a decentralized algorithm, called K_-greedy, based on the Multi-Armed Bandit (MAB) framework, so that it achieves sub-optimal performance by studying the gain for exploring new channel quality information. We implement the prototype of D-Fi on the USRP/ GNURadio to validate the feasibility of our work. The experiments and
- 2. trace-driven simulations show that D-Fi provides up to 3 _ throughput improvement compared to the existing solutions. Existing System: The spatial and temporal diversities, the signals transmitted over a wide frequency band experience independent fluctuations across different frequencies. This phenomenon is generally caused by the frequency selective fading and frequency dependent attenuation. Further, the frequency diversity aware schemes usually require the coordination of the channel access requests from STAs based on the channel estimation results so as to opportunistically harness the frequency diversity, which requires the additional corresponding protocol overhead In short; there is a strict tradeoff between frequency diversity gains and protocol efficiency. Proposed System: Although a variety of approaches have been recently proposed in Wi-Fi networks to achieve frequency diversity awareness none of them explore achieving two objectives, i.e., achieving both frequency diversity and protocol efficiency, simultaneously. Most previous work emphasizes mainly on one side; exploiting frequency diversity with additional channel estimation costs or improving only the
- 3. protocol efficiency (e.g., reducing channel contention cost) by operating at the frequency domain. we present Diversity-aware Wi-Fi (D-Fi), a novel Wi-Fi PHY/MAC protocol that exploits frequency diversity while sustaining protocol efficiency with minimum channel estimation and allocation cost. Specifically, D-Fi synergistically integrates channel information estimation with the channel contention resolution by leveraging an OFDM-based Bloom filter. D-Fi does not require a dedicated channel estimation mechanism. Hardware Requirements: • System : Pentium IV 2.4 GHz. • Hard Disk : 40 GB. • Floppy Drive : 1.44 Mb. • Monitor : 15 VGA Colour. • Mouse : Logitech. • RAM : 256 Mb. Software Requirements: • Operating system : - Windows XP. • Front End : - JSP • Back End : - SQL Server
- 4. Software Requirements: • Operating system : - Windows XP. • Front End : - .Net • Back End : - SQL Server