Lu Xi-Cheng

Compact explicit multi-path routing for LEO satellite networks

The dynamic topology of low Earth orbit (LEO) satellite networks and variable traffic load in different satellite coverage areas pose special challenges to routing algorithm design in the phase of satellite network dimensioning. In this paper, a compact explicit multi-path routing (CEMR) algorithm is proposed. The new algorithm can support traffic load balancing in satellite networks with lower signal overhead compared to traditional multi-path routing algorithm or MPLS through a compact PathID encoding scheme. A PathID validating algorithm is also given to guarantee loop free packet forwarding during transition of time interval. Results from simulations show that CEMR has better performance than other routing schemes in term of end-to-end delay and packet loss probability, and is especially suited to data transferring in case of high traffic load in LEO satellite networks.

The distributed network monitoring model with bounded delay constraints

We address the problem of optimizing a distributed monitoring system and the goal of the optimization is to reduce the cost of deployment of the monitoring infrastructure by identifying a minimum aggregating set subject to delay constraint on the aggregating path. We show that this problem is NP-hard and propose approximation algorithm proving the approximation ratio with lnm+1, where is the number of monitoring nodes. At last we extend our modal with more constraint of bounded delay variation.

A dynamic adaptive replica allocation algorithm in mobile ad hoc networks

In mobile ad hoc networks (MANET), nodes move freely and the distribution of access requests changes dynamically. Replica allocation in such a dynamic environment is a significant challenge. A dynamic adaptive replica allocation algorithm that can adapt to the nodes motion is proposed to minimize the communication cost of object access. When changes occur in the access requests of the object or the network topology, each replica node collects access requests from its neighbors and makes decisions locally to expand replica to neighbors or to relinquish the replica. The algorithm dynamically adapts the replica allocation scheme to a local optimal one. Simulation results show that our algorithms efficiently reduce the communication cost of object access in MANET environment.In mobile ad hoc networks (MANET), nodes move freely and the distribution of access requests changes dynamically. Replica allocation in such a dynamic environment is a significant challenge. The communication cost has become a prominent factor influencing the performance of replica allocation in the MANET environment. In this paper, a dynamic adaptive replica allocation algorithm that can adapt to the nodes motion is proposed to minimize the communication cost of the object access. When changes occur in the access requests of the object or the network topology, each replica node collects access requests from its neighbors and makes decisions locally to expand the replica to neighbors or to relinquish the replica. This algorithm dynamically adjusts the replica allocation scheme towards a local optimal one. To reduce the oscillation of replica allocation, a statistical method based on history information is utilized to choose stable neighbors and to expand the replica to relatively stable nodes. Simulation results show that our algorithms efficiently reduce the communication cost of object access in MANET environment.

FSArch: Enables FPGA-Based Platforms to Provide Network Services

Most network services are provided by middle boxes at present. However middle boxes would cause many issues such as robustness, security and so on. The latest studies put forward the outsourcing mechanism to solve these problems. Given the benefits of FPGA (Field Programmable Gate Array) in reconfiguration and packet processing, we propose Search, an architecture that enables FPGA-based platforms to provide network services. Based on Search, the user can realize customized features added to the network. Besides, we present the idea of FaaS, which takes FPGA-based platforms as the infrastructure to provide network services for users. At last, an application of network measurement service in FaaS is implemented.

A Cluster-Based QoS Multipath Routing Protocol for Large-Scale MANET

To support QoS routing in MANET (mobile ad hoc networks) is a core issue in the research of MANET. Numerous studies have shown the difficulty for provision of quality-of-service (QoS) guarantee in Mobile Ad hoc networks. This paper proposes a scheme referred to a cluster-based QoS multipath routing protocol (CQMRP) that provides QoS-sensitive routes in a scalable and flexible way in mobile Ad Hoc networks. In the strategy, each local node just only maintains local routing information of other clusters instead of any global ad hoc network states information. It supports multiple QoS constraints. The performance of the protocol is evaluated by using the OPNET simulator and the result shows that this protocol can provide an available approach to QoS multipath routing for mobile Ad Hoc networks.