WiFi-based Long Distance (WiLD) networks with links as long as 50–100 km have the potential to provide connectivity at substantially lower costs than traditional approaches. However, real-world deployments of such networks yield very poor end-to-end performance. First, the current 802.11 MAC protocol has fundamental shortcomings when used over long distances. Second, WiLD networks can exhibit h...

Much attention has been given over the past decade to examining the properties of ad-hoc wireless networks. Current trends, however, show that the proliferation of access point (AP) based wireless networks continues to grow, and impending deployments of large-scale AP-based networks in metropolitan areas (see [?] and [?]) speak volumes for their popularity. Given the continued spread of AP-base...

Wireless protocols in the unlicensed spectrum are developed for different requirements in terms of range and power, which makes them difficult to coexist in the same unlicensed spectrum. One such example is Zigbee and WiFi coexistence where low-power Zigbee nodes are frequently starved by WiFi nodes. Recent standardization efforts of short range IEEE 802.11af and long range IEEE 802.22 in the T...

In offices and residential buildings, WiFi networks have become a primary means for providing Internet access to wireless devices whose dominant traffic pattern is unicast. In the meantime, the emergence of network coding has brought about great promises for multicast in communication networks where intermediate nodes are allowed to process independent incoming information flows. Little is know...

Current imaging modalities allow precise visualization of tumors but do not enable quantitative characterization of thetumor metabolic state. Such quantitative information would enhance our understanding of tumor progression andresponse to treatment, and to our overall understanding of tumor biology. To address this problem, we have developed awide-field functional imaging (WiFI) in...

Unlicensed wireless access is becoming increasingly popular because of its low cost. However, different wireless applications have different requirements in terms of range and power, which makes them difficult to coexist in the same unlicensed spectrum. One such example is Zigbee and WiFi coexistence where low-power Zigbee nodes are frequently starved by WiFi nodes. Recent standardization of se...

WiFi-based indoor localization using the fine time measurement (FTM) protocol has become a popular technique. However, in harsh Non-Line-of-Sight (NLoS) environments, WiFi FTM positioning (WFP) suffers from poor performance. In this letter, novel method with assistance of geomagnetic (GP) is proposed. To ensure accuracy GP, an enhanced mind evolutionary algorithm (EMEA) designed. A fine-grained...

Cross-layer design has been proposed to optimize the performance of networks by exploiting the interrelations among parameters and procedures at different levels of the protocol stack. This paper introduces a quantitative framework for the study of cross-layer interactions, which enables design engineers to analyze and quantify interlayer dependencies and to identify the optimal operating point...

Spotify is a large-scale peer-assisted music streaming service. Spotify’s P2P network serves 80% of music data to desktop clients. On the other hand, the rapidly growing number of mobile clients do not use P2P but instead stream all data from Spotify’s servers. We enable P2P on a Spotify mobile client and empirically evaluate the impact of P2P protocols (in particular low-bandwidth traffic betw...

This paper presents a WiFi-aided magnetic matching (MM) algorithm for indoor pedestrian navigation with consumer portable devices. This algorithm reduces both the mismatching rate (i.e., the rate of matching to an incorrect point that is more than 20 m away from the true value) and computational load of MM by using WiFi positioning solutions to limit the MM search space. Walking tests with Sams...