Li Jun Zhang

CSDM · Continuing Professional Studies

Mobility management is one major challenge for wireless network design. Advanced wireless technologies provide mobile nodes with multi-mode radio interfaces, so subscribers can benefit from disparate mobile communication systems. Meanwhile, researchers are putting efforts into standardization of IPv6-based mobility protocols. Hence, wireless networ...

To allow mobile node be always connected regardless of its location on the Internet, mobile IPv6 (MIPv6) is designed for next-generation wireless networks. However, this protocol has some inherent drawbacks: long handoff delay and high packet loss; unbearable for many applications. To improve the performance, mobility protocols such as Fast handove...

This paper presents an overview of IPv6-based mobility management protocols: mobile IPv6 MIPv6, fast handovers for mobile IPv6 FMIPv6, hierarchical mobile IPv6 HMIPv6, and fast handover for hierarchical mobile IPv6 F-HMIPv6. All these protocols play an important role in the next generation wireless networks, because in such networks, mobile users n...

Integrated Network Architecture Design for Next-Generation Wireless Systems; Li Jun Zhang, Liyan Zhang, Laurent Marchand, and Samuel Pierre} Introduction Existing Integrated and Interworking Architecture Interworking Architecture for 3G/WMAN Integrated Architecture for WLAN/WMAN Interworking Architecture for 3G/WLAN Interworking in Heterogeneous...

This chapter provides a survey of IP layer mobility management protocols in next generation wireless networks. In all-IP-based next generation wireless networks, mobile nodes freely change their points of attachment to the network while communicating with correspondent nodes. Hence, mobility management consists of a critical issue, which is to trac...

This paper applies the single microphone speech enhancement method to the microphone array speech enhancement method, and proposes a new speech enhancement method based on autoregressive model (AR). First, for the input matrix, the method adopts the generalized cross correlation method based on onset signals to estimate the time delay. Then accordi...

So far, rapid progress in wireless networking and mobile computing has made possible for mobile users to benefit from disparate wireless systems, such as WPAN, WLAN, WMAN and WWAN. On the other hand, next generation wireless networks are expected to integrate existing wireless systems within its all-IP-based infrastructure while supporting mobility...

A system, a method and a Mobile Node (MN) for enabling a handover of the MN from a current serving access router (PAR) to a next serving access router (NAR) in a data communications network. At least one tunnel is present between the PAR and the NAR to enable data exchange therebetween. The MN has a first address valid under the PAR and is capable...

IEEE 802.11-based wireless local area networks (WLANs) have experienced rapid growth for some years. Increasingly ubiquitous, they are deployed in hotspots such as airports, campuses, shopping malls, providing Internet access for mobile users. Meanwhile, Internet service providers can be endowed with substantial increased productivity by enabling r...

Summary As the radio range of access point (AP) in a wireless local area network (WLAN) is about 35 meters, mobile nodes (MNs) have to frequently undergo a handoff process when they move beyond the radio coverage area of their associated APs. However, legacy IEEE 802.11-based standards cannot provide sufficient support for mobility management. Besi...

Next-Generation Wireless Networks (NGWNs) present an all-IP-based architecture integrating existing cellular networks with Wireless Local Area Networks (WLANs), Wireless Metropolitan Area Networks (WMANs), ad hoc networks, Bluetooth, etc. This makes mobility management an important issue for users roaming among these networks/systems. On one hand,...

Next-generation wireless networks present an all-IP-based architecture integrating the existing cellular networks with wireless local area networks (WLANs), wireless metropolitan area networks (WMANs), wireless ad hoc networks, wireless personal area networks (WPANs), etc. This makes mobility management an important issue for users roaming among th...

Due to the small radio area covered by an Access Point (AP), handoffs frequently occur in Wireless Local Area Networks (WLANs) as Mobile Stations (MSs) move their associations from one AP to another. This paper presents a new handoff management scheme to support ongoing real-time applications while MSs change their network point of attachment. This...

This paper proposes a fast MAC layer handoff scheme with accelerated probe function that reduces handoff latency as well as packet losses in wireless LANs. With this approach, a mobile station (MS) can scan a subset of all channels when it moves beyond the radio range of its current associated access point (AP). Performance evaluation is done throu...

This paper proposes a new protocol, Access Routers Tunneling Protocol, to facilitate seamless vertical handoff between wireless LAN and CDMA2000 access networks. A novel approach called seamless vertical handover for mobile IPv6 (SVHO) is defined to allow a mobile node to resume its real-time ongoing session with its correspondent as soon as it att...

A method and a node for establishing a tunnel with a set of minimal characteristics with a second node in a network. The node comprises a tunneling protocol module that determines a first set of desired characteristics and comprising a sub-option indicating a need for an authentication characteristic. The tunneling protocol module sends a tunnel re...

This paper presents a new protocol, namely Access Routers Tunneling Protocol (ARTP), dedicated to pre-configuring bidirectional secure tunnels among adjacent access routers before handoff. This protocol allows two tunnel endpoints to negotiate quality of service-related parameters, traffic classification aspects, security policies, such as authenti...

Among other things, using the handover mechanism in accordance with the present invention enables communications to be closer to unperturbed. In fact, the present handover mechanism reduces the time during which the MN is not reachable and tends to avoid extensive procedures of address binding. It further reduces the likelihood of costly context re...