Xiaonan Wang

Research on all-IP communication between wireless sensor networks and IPv6 networks

This paper proposes a scheme for achieving all-IP communication between wireless sensor networks and IPv6 networks. The network architecture based on trees is proposed. Based on the architecture, the hierarchical IPv6 address structure is created and the address configuration algorithm is proposed. During the address configuration process, the trees are also established simultaneously. Based on the hierarchical address structure, the routing algorithm is proposed. In the algorithm, the routing can be performed automatically through the trees in the link layer. The paper analyzes the schemes performance parameters and the data results show that the performance of the scheme is better.

An IPv6 address configuration scheme for wireless sensor networks

The paper proposes an IPv6 address configuration scheme for wireless sensor networks. The paper creates an IPv6 address structure for sensor nodes, and based on the proposed IPv6 address structure, the paper proposes an IPv6 address auto-configuration scheme. In the scheme, the transmission scope of the control packets is controlled within one-hop scope and the scheme neither records the address allocation status nor performs the duplicate address detection, so the address configuration cost is reduced and the address configuration delay is shortened. In addition, based on the proposed IPv6 address structure, the paper proposes the address recovery algorithm. From the perspectives of the address configuration cost and address configuration delay, the paper analyzes and compares the performance parameters of the proposed scheme and the existing schemes, including MANETConf, Strong DAD, LISAA and IAC. The analytical and simulative results show that the performance of the proposed scheme is better.

An address configuration protocol for 6LoWPAN wireless sensor networks based on PDAD

Abstract In a wireless sensor network (WSN), data collected by a sensor node need to be associated with location information in order to support real-world applications. Taking the WSN characteristics into account, this paper proposes an address configuration scheme based on location information and passive duplicate address detection (PDAD). In this scheme, the network architecture based on location information is presented, and based on this architecture the address initialization algorithm and address maintenance algorithm are proposed. The address initialization algorithm is performed once the network starts, and it is made up of the initialization address configuration sub-algorithm (IAC) and the initialization location PDAD sub-algorithm (ILPDAD). The address maintenance algorithm is performed after the initialization algorithm is complete, and it is composed of the maintenance address configuration sub-algorithm (MAC) and the maintenance location PDAD sub-algorithm (MLPDAD). During the address initialization process (address maintenance process), a new node first uses IAC (MAC) to obtain an address and then performs ILPDAD (MLPDAD) to ensure the address uniqueness. Since beacon frames are employed to achieve IAC (MAC) and ILPDAD (MLPDAD), the address configuration cost and delay are reduced. Moreover, IAC (MAC) is based on location information and ILPDAD (MLPDAD) is based on PDAD, so there are always the sufficient address resources for address configuration without address reclamation. In this way, the extra cost and delay caused by both the address reclamation and the address configuration failure are avoided. This paper evaluates the performance of this scheme, and the data results show that this scheme effectively reduces the address configuration delay and cost.

Mobility support for vehicular networks based on vehicle trees

Abstract The high speed of vehicles results in frequent mobility handovers which degrade communication quality, so it is significant to reduce the handover latency in a vehicular network. Taking this objective into account, this paper proposes a mobility handover scheme based on vehicle trees. In this scheme, a vehicle tree is made up of a few vehicles and performs the handovers as a unit. Consequently, the vehicles in a vehicle tree can be configured with a care-of address only through one addressing operation, and the address binding operations for these vehicles can be performed in parallel. Moreover, the vehicles in a vehicle tree can perform the link-layer handovers only via one channel scanning operation. The performance of the proposed scheme is evaluated, and the data results show that this scheme can greatly reduce the handover delay.

Mobility management for 6LoWPAN WSN

Abstract When a wireless node moves across different IP domains, it needs to perform both the handover in the link layer (L2) and the handover in the network layer (L3). The L2 handover is responsible for the channel switch, and the L3 handover takes charge of the IP address change to ensure the communication correctness. The L2 handover and the L3 handover are two independent processes which are performed in series, so the total handover delay is equal to the sum of the L2 handover delay which is mainly caused by channel scanning and the L3 handover delay which is primarily incurred by care-of address (CoA) configuration. This considerable total handover latency causes severe packet loss, so it is significant to reduce the total handover latency. This paper proposes a cross-layering mobility management scheme to reduce the total handover delay and it has the following contributions: (1) This scheme combines the L3 handover with the L2 one so that they can be performed in parallel. (2) A CoA is pre-configured and the channel information is acquired in advance so that the L3 handover can be achieved without CoA configuration and the L2 handover can be performed without channel scanning. The performance of this scheme is evaluated, and the results show that this scheme effectively reduces the total handover latency.

Addressing for 6LoWPAN based on multi-hop clusters

6LoWPAN is a multi-hop network, so the address configuration standards commonly used in single-hop IP networks cannot directly be applied in 6LoWPAN. In this situation, some addressing solutions for 6LoWPAN are proposed. Since these solutions employ the stateless strategy such as duplicate address detection (DAD) or the stateful strategy such as a remote server, the addressing cost and latency are relatively high. This paper proposes an addressing scheme based on multi-hop clusters and aims to reduce the total addressing cost and delay. In this scheme, a cluster covers a multi-hop area, so the frequency of a node performing the addressing is lowered and the total addressing cost and delay are reduced. Moreover, a node employs beacons to obtain a unique address from a neighbour without DAD, so the addressing cost and delay are further reduced. This scheme is evaluated, and the data results show that the average addressing success rate is increased and the total addressing cost and delay are reduced.

Reliable routing in IP-based VANET with network gaps

Abstract In a route with a network gap, a vehicle usually drops messages if it cannot find the next hop. In this case, communications may be disrupted. Therefore, it is very important to avoid network gaps when routing paths are established. This paper proposes a reliable routing scheme and aims to establish routing paths without network gaps to improve the packet delivery rate. In this scheme, a routing establishment algorithm based on road segments and virtual nodes is proposed. This algorithm can establish the routing paths without network gaps, so the packet loss caused by network gaps is avoided. Moreover, a message can be transmitted along the shortest routing path without a network gap, so the packet delivery rate is improved. Finally, this scheme is evaluated, and the data results show that the packet delivery rate is effectively improved.

All-IP WSN backbone formation based on location information

This paper proposes an all-IP WSN formation scheme based on location information. In the scheme, the all-IP WSN architecture based on location information is proposed and it can use a small number of backbone nodes to cover the entire WSN area, so the network formation cost and delay are reduced. Based on the architecture, the backbone node election algorithm and the backbone tree formation algorithm are proposed. Through a backbone tree, the routing can be achieved without either route discovery or routing information storage. Based on the architecture, the backbone tree maintenance algorithm is also proposed to maintain the backbone tree topology so that the routing correctness can be ensured. The performance parameters of this proposal are evaluated and compared, and the data results show that this proposal effectively reduces the network formation delay and cost.

A route optimisation scheme for 6LoWPAN nested mobile networks

The paper proposes a scheme for route optimisation for 6LoWPAN nested mobile wireless networks. In the scheme, a mobile node in a mobile wireless network can communicate with a correspondent node without going through any corresponding mobile routers home agents or establishing a tunnel, which reduces the data transmission cost and shortens the data transmission delay time. The scheme creates the hierarchical structure for a mobile routers care-of address, and proposes the IPv6 address configuration algorithm based on the shortest path strategy. In addition, a node in a mobile wireless network can correctly determine the location of a correspondent node according to the correspondent node

Optimal addressing-based routing for 6LoWPAN

s IPv6 address. Therefore, an optimal routing path to the correspondent node can be established automatically through the proposed 6LoWPAN network topology, which reduces the energy consumption for establishing the routing paths. From the perspectives of theory and simulation, the paper analyses the proposed scheme