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Most existing production vehicle tracking services rely on the Global Positioning System (GPS) and a proprietary server/client infrastructure. This type of inflexible and centralized architecture incurs severe vender-dependency and high service cost. In this paper, we propose a cost-effective decentralized vehicle remote positioning and tracking system architecture. This architecture only consists of two components: (1) a vehicle terminal for collecting real-time vehicle location from a navigation satellite system and report it to a user terminal via the existing mobile network and (2) a user terminal on a mobile phone for analyzing the location information from (1) and inform the owner. We prototype the positioning and tracking system using the BeiDou Navigation Satellite System (BDS) and Global System for Mobile Communication(GSM) Network. Experiment results illustrate that the system is capable of tracking vehicle location and warning the owner if the vehicle unexpectedly moves more than 100 m at low cost. With maximum vender-neutrality and high-availability as the design philosophy, the system is able to utilize multiple available navigation satellite systems and mobile networks.

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The past few years have witnessed debate on how to improve link utilization of high-speed tiny-size buffer routers. Widely argued proposals for TCP traffic to realize acceptable link capacities mandate: (i) over-provisioned core link bandwidth; and (ii) non-bursty flows; and (iii) tens of thousands of asynchronous flows. However, in high speed access networks where flows are bursty, sparse and synchronous, TCP traffic suffer severely from routers with tiny buffers.We propose a new congestion control algorithm called Desynchronized Multi-Channel TCP (DMCTCP) that creates a flow with multiple channels. It avoids TCP loss synchronization by desynchronizing channels, and it avoids sending rate penalties from burst losses. Over a 10 Gb/s large delay network ruled by routers with only a few dozen packets of buffers, our results show that bottleneck link utilization can reach 80% with only 100 flows. Our study is a new step towards the deployment of optical packet switching networks.