In the project, we shall investigate how network coding can increase the reliability and flexibility, and decrease network traffic and delay of distributed storage and content dissemination in heterogeneous mobile networks, where user terminals have limited storage space and bandwidth. Through the Deviceto-device and cloud storage technology, the efficiency of media storage and dissemination can be significantly increased. The network coding can allow the maximum (capacity-achieving) flow, flexibility and security. This project studies how the wireless environments affecting the network storage and transmission with network coding. That is, the topology of networks is more heterogeneous and dynamic. The cost (economic cost, capacity) of each transmission link may be different. The storage space of caching nodes may be various too. We also investigate how the delay will be improved by network coding. The channels of the networks are unreliable. The delay and bandwidth for certain specific application will be considered. Different cooperative approaches among sources, caching node and ending users will be investigated. For instance, machine-to-machine communications will be allowed to further reduce the delay. We shall study the efficient network coding scheme for such scenario. The results of the project are expected to increase the transmission and storage efficiency of wireless networks.
Last Updated on Wednesday, 30 November 2011 10:46
The use of on-board passenger internet on trains is steadily increasing and today passenger surveys show that it is more important that the on-board wireless internet is functioning than that the train is on time!
Today the most common solution to provide speech and 2G/3G connectivity on board trains is with the help of simple 2G/3G amplify-and-forward repeater systems. However, increasingly train operators in Europe are more and more often using a system’s solution (provided by icomera) that enables simultaneously connectivity with multiple radio carriers at different frequencies, standards and by different operators. The system then aggregates all of the received capacity on an IP level into one “big pipe” which is then through a WiFi system distributed in the train. Using standard HSPA technology, this combination of carriers results today in an aggregated channel of up to about 50Mbps.
50Mbps throughput to 250 passengers inside an X-2000 may be a good enough solution today but probably not when a service like e.g. individual HDTV is being required. Assuming that passengers in a 5-10 years time frame will require access to at least 4Mbps services from the outside world we may estimate that each high speed train, travelling at 2-300km/h will need to be connected with at least 1Gbps.
In this project we study the plausibility of providing up to 1Gbps connectivity to trains using MIMO and Coordinated Multi-Point (CoMP) transmission in LTE-A. The study is conducted in collaboration with Ascom, Delta Node and Icomera, using real measurements on board an X-2000 high speed train.
Project partners: Icomera, Delta Node, Ascom and Wireless@KTH
Project manager and contact person: Claes Beckman, Wireless@KTH,
Link to the Gigabit Internet of trains project website
IN BRIEF The main research focus of Wireless@KTH is to solve key technical problems in systems in Infrastructure for Mobile Services and Systems for Mobile Service of tomorrow. Not only physical constraints (i.e. physics of radio propagation, capacity limitations in networks etc) are considered in our research In designing future systems for mobile service, end-user and service provider demands, constraints and business logic also have to be modeled and considered to make an adequate and sustainable technical design.
