Search

The coexistence of heterogeneous devices in wireless networks brings a new topic on cross-technology communication (CTC) to improve the coexistence efficiency and boost collaboration among these devices. Current advances on CTC mainly fall into two categories, physical-layer CTC and packet-level energy modulation (PLEM). The physical-layer CTC achieves a high CTC data rate, but with channel incompatible to commercial devices, making it hard to be deployed in current wireless networks. PLEM is channel and physical layer compatible, but with two main drawbacks of the low CTC data rate and MAC incompatibility, which will induce severe interference to the other devices’ normal data transmissions. In this paper, we propose symbol-level energy modulation (SLEM), the first CTC method that is fully compatible with current devices in both channel and the physical/MAC layer processes, having the ability to be deployed in commercial wireless networks smoothly. SLEM inserts extra bits to WiFi data bits to generate the transmitting bits, so as to adjust the energy levels of WiFi symbols to deliver CTC information. We make theoretical analysis to figure out the performance of both CTC and WiFi transmissions. We also conduct experiments to demonstrate the feasibility of SLEM and its performance under different network situations. [ABSTRACT FROM AUTHOR]

This paper represents the design, feasibility evaluation, and performance validation of ICMR, a novel cross layer protocol that can maximize concurrent transmissions and avoid data frame interference in wireless networks, achieving a higher throughput comparing with the 802.11 standard and other state-of-the-art protocols. Observations on the 802.11 standard reveal that nodes around both the transmitter and receiver of the ongoing link waste concurrent transmission opportunities, degrading the network throughput dramatically. A state-of-the-art protocol IRMA is proposed to improve the network throughput through exploiting concurrent transmissions at the transmitter side. In this paper, a new ICMR protocol focuses on the receiver side to further improve the network throughput, through exploiting discernible interference cancellation, a physical layer mechanism that can successfully detect data frames when collided by control frames. We analyze the concurrent transmission opportunities of one link from the transmitter's transmission opportunities and the receiver's reception opportunities, then formulate the opportunities and give theoretical analysis to indicate that ICMR will have a higher opportunity over other protocols. Feasibility of the discernible interference cancellation mechanism is demonstrated through experiment results based on USRP2, and the throughput improvement of ICMR comparing with the other protocols is confirmed through simulations based on ns-2. [ABSTRACT FROM AUTHOR]

Wireless networks are propelled to improve the network throughput effectively to face the challenge of sustaining the rapid growth of data traffic and the high density of wireless nodes. Exposed terminals are a main source in wireless networks that degrades the network throughput performance through excessively avoiding interferences and forbidding concurrencies. To combat the exposed terminal problem and exploit the concurrent transmissions in wireless networks, we present the design of Interference Resistant Multiple Access (IRMA) in this paper, which can achieve higher throughput compared to the 802.11 standard. By observing that nodes in current protocols waste transmission opportunities in two different scenarios, IRMA exploits the concurrency in two aspects. IRMA proposes a signature detection method in the physical layer to combat control frames’ collisions, thus exploits the concurrency at the transmitter side. IRMA also designs a new NAV update scheme in the MAC layer to differentiate the interference ranges of different transmission links, thus exploits the concurrency of all non-interfering links. Experimental results based on USRP2 demonstrate the feasibility of the signature detection method, and simulations based on ns-2 show that IRMA outperforms the 802.11 standard and other protocols significantly. [ABSTRACT FROM AUTHOR]