共查询到10条相似文献,搜索用时 140 毫秒
1.
This paper considers the support of real-time services to mobile users in an Integrated Services Packet Network. In the currently existing architectures, the service guarantees provided to the mobile hosts are mobility dependent, i.e., mobile hosts experience wide variation in the quality of service and often service disruption when hosts move from one location to another. The network performance degrades significantly when mobile hosts are provided with mobility independent service guarantees. In this paper we have proposed a service model for mobile hosts that can support adaptive applications which can withstand service degradation and disruption, as well as applications which require mobility independent service guarantees. We describe an admission control scheme for implementing this service model and evaluate its performance by simulation experiments. Simulation results show that, if sufficient degree of multiplexing of the mobility dependent and independent services are allowed, the network does not suffer any significant performance degradation and in particular our admission control scheme achieves high utilization of network resources. 相似文献
2.
The Mobile IPv6 (MIPv6) provides many great features, such as sufficient addressing space, mobility, and security; MIPv6 is one of the most important protocols for next generation mobile Internet. Simultaneously, with the rapid improvement of wireless technologies, the real-time multi-media IP services such as video on demand, videoconference, interactive games, IP telephony and video IP phone will be delivered in the near future. Thus, to furnish accurate QoS for real-time services is one of the most important thing in the next generation mobile Internet. Although RSVP, which is a resource reservation protocol, processes signaling messages to establish QoS paths between senders and receivers, RSVP was originally designed for stationary networks and not aware of the mobility of MNs. Therefore, this paper proposes a novel RSVP extension to support real-time services in Hierarchical Mobile IPv6 (HMIPv6) environments. For intra-site mobility, the concept of QoS Agent (QA) is proposed to handle the RSVP QoS update messages and provide the advanced reservation models for real-time services. For inter-site mobility, IP multicast can help to invite inter-site QAs to make pre-reservation and minimize the service disruption caused by re-routing the data path during handover. Simulation results show that the proposed scheme over HMIPv6 is more suitable for real-time services than the famous RSVP tunnel-based solution. 相似文献
3.
4.
Multimedia and real-time applications require bandwidth guarantees, which can be achieved by resource reservation. However, bandwidth reservation in ad-hoc networks is a very challenging task due to the instability of radio channels, node mobility and lack of coordination between mobile nodes. Most proposed reservation protocols focus on point-to-point reservations, and only a few work has been done to propose an efficient end-to-end reservation scheme. In this paper, we propose a reservation scheme called End-to-end reservation scheme for voice and data traffic support (EERV). The basic component of our protocol is a handshake mechanism which has the role to establish point-to-point reservations, and to ensure consistency of reservations between neighbor nodes. Both data and voice sources are allowed to establish reservations with priority given to voice sources. This reservation scheme is extended to support the reservation and release of resources along a path in cooperation with the routing layer. Our reservation scheme is based on DSR, a well-known reactive routing protocol. Mobility of nodes and node failure cause frequent reservation breakages resulting in significant performance degradation. In order to resolve this issue we propose a reservation loss detection and reservation recovery mechanisms. We achieved intensive simulations to evaluate the performance of our protocol. Simulation results show the effectiveness of this protocol. 相似文献
5.
Yi Sun Yucheng Zhang Yilin Song Eryk Dutkiewicz 《Wireless Personal Communications》2011,60(4):769-807
In recent years, with the development of mobile communication technologies and the increase of available wireless transmission
bandwidth, deploying multimedia services in next generation mobile IPv6 networks has become an inevitable trend. RSVP (resource
reservation protocol) proposed by the IETF is designed for hardwired and fixed networks and can not be used in mobile environments.
This paper proposes a protocol, called Fast RSVP, to reserve resources for mobile IPv6. The protocol adopts a cross-layer
design approach where two modules (RSVP module and Mobile IPv6 module) at different layers cooperate with each other. Fast
RSVP divides a handover process with QoS guarantees into two stages: (1) setup of the resource reservation neighbor tunnel
and (2) resource reservation on the optimized route. It can help a mobile node realize fast handover with QoS guarantees as
well as avoid resource wasting by triangular routes, advanced reservations and duplicate reservations. In addition, fast RSVP
reserves “guard channels” for handover sessions, thus greatly reducing the handover session forced termination rate while
maintaining high performance of the network. Based on extensive performance analysis and simulations, Fast RSVP, compared
with existing methods of resource reservation in mobile environments, performs better in terms of packet delay and throughput
during handover, QoS recovery time after handover, resource reservation cost, handover session forced termination rate and
overall session completion rate. 相似文献
6.
Dynamic QoS Allocation for Multimedia Ad Hoc Wireless Networks 总被引:1,自引:0,他引:1
In this paper, we propose an approach to support QoS for multimedia applications in ad hoc wireless network. An ad hoc network is a collection of mobile stations forming a temporary network without the aid of any centralized coordinator and is different from cellular networks which require fixed base stations interconnected by a wired backbone. It is useful for some special situations, such as battlefield communications and disaster recovery. The approach we provide uses CSMA/CA medium access protocol and additional reservation and control mechanisms to guarantee quality of service in ad hoc network system. The reason we choose CSMA protocol instead of other MAC protocols is that it is used in most of currently wireless LAN productions. Via QoS routing information and reservation scheme, network resources are dynamically allocated to individual multimedia application connections. 相似文献
7.
Kam Lee 《Wireless Networks》1996,2(3):205-217
Owing to widespread user mobility, limited radio resources, and changing network characteristics, supporting multimedia communications in a mobile internetworking environment is a challenging problem. In this paper, we present an adaptive reserved service framework for use in integrated services networks to support mobile connections carrying multimedia traffic. Integrated in the framework are an anticipatory handoff control mechanism which enables fast handoff, and an adaptive link partitioning scheme which enhances handoff success. Besides, bandwidth reservations in the wireline network are dynamically adjusted based on resource availability in the wireless networks. An accompanying reservation protocol not only facilitates distributed control of mobile connections but also provides network feedback to mobile hosts.An earlier version of this paper appeared in the First International Conference on Mobile Computing and Networking, 1995. 相似文献
8.
The Universal Mobile Telecommunications System (UMTS) all-IP network supports IP multimedia services through the IP Multimedia Subsystem (IMS). This paper proposes a mobile Quality-of-Service (QoS) framework for heterogeneous IMS interworking. To reduce the handoff disruption time, this framework supports the IMS mobility based on the concept of Session Initiation Protocol (SIP) multicast. In our approach, the mobility of a User Equipment (UE) is modeled as a transition in the multicast group membership. With the concept of dynamic shifting of the multicast group's members, the flow of actual data packets can be switched to the new route as quickly as possible. To overcome mobility impact on service guarantees, UEs need to make QoS resource reservations in advance at neighboring IMS networks, where they may visit during the lifetime of the ongoing sessions. These locations become the leaves of the multicast tree in our approach. To obtain more efficient use of the scarce wireless bandwidth, our approach allows UEs to temporarily exploit the inactive bandwidths reserved by other UEs in the current IMS/access network. Analytic and simulation models are developed to investigate our resource reservation scheme. The results indicate that our scheme yields comparable performance to that of the previously proposed channel assignment schemes. 相似文献
9.
Multi-hop mobile wireless networks have been proposed for a variety of applications where support for real-time multimedia
services will be necessary. Support for these applications requires that the network is able to offer quality of service (QoS)
appropriate for the latency and jitter bounds of the real-time application constraints. In this paper, we analyze the primary
challenges of realizing QoS in mobile wireless networks with heterogeneous devices and propose a QoS framework for real-time
traffic support. We address the problem in three ways: estimate the path quality for real-time flows, mitigate the impact
of node heterogeneity on service performance, and reduce the impact of interfering non-real-time traffic. Specifically, our
proposed QoS framework first utilizes a call setup protocol at the IP layer to discover paths for real-time flows, as well
as to perform admission control by accurate service quality prediction. The underlying routing protocol also enables transparent
path selection among heterogeneous nodes to provide stable paths for real-time traffic delivery. We then use a prioritized
MAC protocol to provide priority access for flows with real-time constraints to reduce interference from unregulated non-real-time
traffic. We foresee the utility of our proposed solution in heterogeneous mobile networks, such as campus or community-wide
wireless networks. In these environments, resource-rich or fixed wireless routers may be leveraged to achieve better service
quality when heterogeneity of node capability and movement is significant. Through experimental results, we demonstrate the
utility and efficiency of our approach.
Yuan Sun received her Ph.D. from the Department of Computer Science at the University of California, Santa Barbara in 2005. She worked
with Prof. Elizabeth Belding-Royer in the MOMENT Lab. Her thesis work focused on providing QoS for mobile networks. Dr. Sun
is currently employed at Google.
Elizabeth M. Belding-Royer is an Associate Professor in the Department of Computer Science at the University of California, Santa Barbara. Elizabeth’s
research focuses on mobile networking, specifically ad hoc and mesh networks, multimedia, monitoring, and advanced service
support. She is the founder of the Mobility Management and Networking (MOMENT) Laboratory (moment.cs.ucsb.edu) at UCSB. Elizabeth
is the author of over 50 papers related to mobile networking and has served on over 40 program committees for networking conferences.
Elizabeth served as the TPC Co-Chair of ACM MobiCom 2005 and IEEE SECON 2005, and is currently on the editorial board for
the IEEE Transactions on Mobile Computing. Elizabeth is the recipient of an NSF CAREER award, and a 2002 Technology Review
100 award, awarded to the world’s top young investigators. See ebelding for further details.
Xia Gao is currently a Staff Engineer at Ubicom. He received his Ph.D of ECE from the University of Illinois at Urbana-Champaign
in 2001. Before joining Ubicom, he had worked in DoCoMo Communications Laboratory for 4 years where he conducted research
on 3G-4G wireless communication system and handset technologies and WiFi systems. He has published more than 30 conference
and journal papers. He has chaired several International conferences and served as TPC members for many others. He is a member
of IEEE and a honored member of Sigma Xi.
James Kempf is a Research Fellow at DoCoMo USA Laboratories. He holds a Ph.D. from the University of Arizona, Tucson, AZ. Previously,
James worked at Sun Microsystems for 13 years, and contributed to numerous research projects involving wireless networking,
mobile computing, and service discovery. James is a former member of the Internet Architecture Board, and co-chaired the SEND
and Seamoby IETF Working Groups. James continues to be an active contributor to Internet standards in the areas of security
and mobility for next generation, Internet protocol-based mobile systems. 相似文献
10.
Currently, the RSVP model, which is efficient resource reservation in the fixed endpoints, becomes invalid under host mobility. We investigate the problems of standard RSVP in providing real-time services in wireless mobile networks. We also observe carefully how to interoperate IntServ services over DiffServ networks, and how to map IntServ QoS parameters into a wireless link. We then identify the advantages and drawbacks of the existing RSVP proposals to support QoS under both micromobility and macromobility. We finally propose a dynamic resource allocation scheme for reducing service disruption of real-time applications due to frequent mobility of a host 相似文献