共查询到20条相似文献,搜索用时 359 毫秒
1.
Multicasting is a desired function in both wired and wireless networks. Currently, multicasting‐based applications have pervasive
presence and influence in our Internet. Wireless ATM aims to support different traffic types over a high speed wireless network.
In particular, traditional approaches towards multicasting in wired networks cannot be directly applied to mobile ATM networks.
This includes the mechanism proposed to handle mobility in wired networks. In this paper, we address the issues behind multicasting
in wireless ATM networks and the underlying mechanisms to support handoffs of both unicast and multicast connections. Through
simulation, we evaluated the performance of optimal core‐based tree (CBT), late‐joined CBT, optimal source‐based tree (SBT),
and late‐joined SBT during changing multicast host membership conditions. In addition, we evaluated the impact of multicast
receivers' migration on the total link cost of the resultant multicast tree. Simulation results revealed that source‐based
trees incur more total link costs under both dynamic host membership and receivers' migration scenarios. However, it generates
less control messages than the distributed CBT and SBT approaches.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
2.
A signaling architecture for wireless ATM access networks 总被引:1,自引:0,他引:1
Loukas Nikos H. Passas Nikos I. Merakos Lazaros Venieris Iakovos S. 《Wireless Networks》2000,6(2):145-159
A multiservice wireless Asynchronous Transfer Mode (ATM) access system is considered from a signaling protocol viewpoint.
In an attempt to generalize and extend results and experiences obtained from the specification, design, and implementation
of fixed ATM‐based access networks, we extend the concept of the broadband V interface (referred to as VB) for application
to wireless ATM access networks. The proposed architecture follows the signaling structure of Broadband ISDN (B‐ISDN) User–Network
Interface (UNI), thus offering the possibility for integration of the wireless ATM access system into fixed B‐ISDN. It is
shown that the use of the proposed access signaling architecture provides cost effective implementations without degrading
the agreed Quality of Service (QoS), and simplifies call/connection and handover control. The evaluation of the proposed access
signaling protocol structure yields results that fall within acceptable ATM signaling performance measures. A performance
comparison of our approach with an alternative access signaling configuration is also carried out to quantify the relative
gains.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
3.
The flexibility offered by the ATM transport mechanism and its potential capabilities, together with its compatibility with
the B‐ISDN, makes ATM the prime candidate for the support of multimedia services over the wireless medium. However, technical
issues remain to be resolved in relation to the feasibility of ATM for the support of mobility over the radio interface. This
paper examines network issues in supporting handover in a wireless ATM network. In particular, analysis has been performed
for a virtual tree-based network architecture. Results have shown that by using multicast transmission and by using a distributed
numbering algorithm, the potential problems of cell-loss and cell-duplication have been eliminated.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
4.
The major challenges of designing multicast traffic control protocols for a combined wired/wireless network are the varying
transmission characteristics (bandwidth, error, and propagation delay) of the wireless and wired media, and the different,
possibly conflicting frame rate requests from multiple sources. To address these issues, in this paper we design and evaluate
new unicast and multicast guaranteed frame rate (GFR) schemes for supporting TCP/IP traffic over a combined wired/wireless
ATM network. We first propose a new, flexible weighted buffer management, and a frame‐based virtual spacing (VS) mechanism
implementing weighted fair queueing. The unicast GFR scheme is based on the integration of the new weighted buffer management,
and either cell‐based or frame‐based VS. It is then extended to support multicast GFR flows. The multicast scheme presented
in this paper is the first multicast GFR scheme appeared in the literature. These schemes are carefully evaluated over several
network configuration, supporting heterogeneous TCP/IP traffic with various frame rates. Simulation results show that the
new schemes guarantee the minimum rates requested, provide excellent fairness, and achieve reasonably high efficiency. The
new schemes may be extended to provide differentiated service in both IP and mobile IP frame work.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
5.
各种传统的远程访问VPN方案(包括IPSec-VPN和SSL-VPN)都只是为固网环境下外出企业员工的"游牧访问"而设计的,它不适合于未来的移动无线网络场景.本文针对移动无线场景中特有的无线终端计算能力和网络带宽限制等问题,提出了一种基于WTLS安全协议的轻型移动VPN方案.该移动VPN方案支持移动节点在不同无线接入网络之间的自由切换,允许外出企业员工在任何时间、任何地点、使用最佳的无线接入网络连接到企业网络并安全地访问企业内部资源. 相似文献
6.
A new ATM adaptation layer for TCP/IP over wireless ATM networks 总被引:3,自引:0,他引:3
This paper describes the design and performance of a new ATM adaptation layer protocol (AAL‐T) for improving TCP performance
over wireless ATM networks. The wireless links are characterized by higher error rates and burstier error patterns in comparison
with the fiber links for which ATM was introduced in the beginning. Since the low performance of TCP over wireless ATM networks
is mainly due to the fact that TCP always responds to all packet losses by congestion control, the key idea in the design
is to push the error control portion of TCP to the AAL layer so that TCP is only responsible for congestion control. The AAL‐T
is based on a novel and reliable ARQ mechanism to support quality‐critical TCP traffic over wireless ATM networks. The proposed
AAL protocol has been validated using the OPNET tool with the simulated wireless ATM network. The simulation results show
that the AAL‐T provides higher throughput for TCP over wireless ATM networks compared to the existing approach of TCP with
AAL 5.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
7.
Mobile ATM offers a common wired network infrastructure to support mobility of wireless terminals, independent of the wireless access protocol. In addition, it allows seamless migration to future wireless broadband services, such as wireless ATM, by enabling mobility of end-to-end ATM connections. In spite of the diversity in mobile networking technologies (e.g., cellular telephony, mobile-IP, packet data services, PCS), all of them require two fundamental mechanisms: location management and handoff. This article describes different schemes for augmenting a wired ATM network to support location management of mobile terminals and handoff protocols for rerouting a connection data path when the endpoint moves. A prototype implementation of mobile ATM integrating mobility support with ATM signaling and connection setup, is presented. It shows how mobile ATM may be used to provide mobility support to an IP terminal using non-ATM wireless access 相似文献
8.
B. Pauwels 《International Journal of Communication Systems》1989,2(1):49-59
This paper addresses the topic of signalling and connectionless data transfer virtual channels in ATM at the UNI. It recapitulates on the access signalling support in narrowband ISDN, as a representative of an STM network and the predecessor of the coming broadband ISDN. Also, the influence of the customer premises network architecture is taken into account. From there, it is investigated in which ways these principles can be extended, into a general access infrastructure and access configuration management for signalling and connectionless services in the ATM-based broadband ISDN. Some possible implications for the internal architecture of the CPN and the network are discussed. This brings some insight into the restrictions which standardization of these principles at the UNI may bring along for the architecture. 相似文献
9.
In a wireless ATM system, a network must provide seamless services to mobile users. To support this, mobility function should
be added to existing ATM networks. Through a handoff operation, a mobile user can receive a service from the network without
disconnecting the communication. A handoff results in connection path rerouting during an active connection. To avoid cell
loss during a handoff, cell buffering and rerouting are required in the network. A handoff switch is a connection breakdown
point on an original connection path in the network from which a new connection sub‐path is established. It performs cell
buffering and rerouting during a handoff. Cell buffering and rerouting can introduce a cell out‐of‐sequence problem. In this
paper we propose a handoff switch architecture with a shared memory. The architecture performs cell buffering and rerouting
efficiently by managing logical queues of virtual connections in the shared memory and sorting head‐of‐line cells for transmission,
thus achieving in‐sequence cell delivery during a handoff. We also present simulation results to understand the impacts of
handoffs on switch performance.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
10.
Architecture and experimental results for quality of service in mobile networks using RSVP and CBQ 总被引:3,自引:0,他引:3
Efforts are underway to enhance the Internet with Quality of Service (QoS) capabilities for transporting real‐time data. The
issue of wireless networks and mobile hosts being able to support applications that require QoS has become very significant.
The ReSerVation Protocol (RSVP) provides a signaling mechanism for end‐to‐end QoS negotiation. RSVP has been designed to work
with wired networks. To make RSVP suitable for wireless networks, changes need to be made by: (i) changing the way control
messages are sent, and (ii) introducing wireless/mobile specific QoS parameters that take into account the major features
of wireless networks, namely, high losses, low bandwidth, power constraints and mobility. In this paper, an architecture with
a modified RSVP protocol that helps to provide QoS support for mobile hosts is presented. The modified RSVP protocol has been
implemented in an experimental wireless and mobile testbed to study the feasibility and performance of our approach. Class
Based Queueing (CBQ) which is used as the underlying bandwidth enforcing mechanism is also modified to fit our approach. The
experimental results show that the modified RSVP and CBQ help in satisfying resource requests for mobile hosts, after handoff
occurs. The experiments also show how different power and loss profile mechanisms can be used with our framework. The system
performance using the modified RSVP control mechanism is also studied.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
11.
A novel network architecture based on the IEEE 802.6 metropolitan area networks (MAN) is proposed to integrate the wireless
and wired segments of a regional enterprise network (REN) within a city. This architecture functions like a distributed switch
for all types of services, reducing traffic congestion by sharing the high capacity link dynamically and facilitating signaling,
mobility management, call processing and network management through its distributed functions, transport facilities and broadcasting
capability. It also serves as a peripheral gathering network of REN traffic for transport over a wide area ATM/BISDN, enabling
integration of an enterprise's regional networks into a global EN. Two major wireless applications, i.e., wireless PABX (WPABX)
and wireless LAN (WLAN) are discussed to illustrate the advantages of this MAN‐based architecture. Although a REN is likely
to support a wide range of different services, voice and data will continue to be the predominant traffic generated by WPABXs
and WLANs, respectively, and are also representative of isochronous and asynchronous multimedia traffic carried by future
wireless networks. We compare the traffic capacity of several voice transport alternatives under integrated (voice/data) network
traffic with various data traffic loads, and study voice and data integration under three different integration schemes by
simulations. Results indicate that the MAN‐based architecture is most effective employing queue arbitrated (QA) access for
asynchronous traffic, pre‐arbitrated access for constant bit‐rate isochronous traffic, and the new reservation arbitrated
(RA) access for variable bit‐rate isochronous traffic, under a scheme that permits full sharing between QA and RA traffic.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
12.
One of the major design issues in wireless ATM is the support of inter‐switch handoff. An inter‐switch handoff occurs when
a mobile terminal moves to a new base station connecting to a different switch. Recently, a two‐phase handoff protocol has
been proposed to support inter‐switch handoff in wireless ATM networks. With the aim of shortening handoff delay while using
the network resources efficiently, the two‐phase handoff protocol employs path extension for each inter‐switch handoff, followed
by path optimization if necessary. To implement the two‐phase handoff protocol efficiently, we need to determine when to trigger
path optimization. In this paper, we propose and analyze three path optimization schemes, namely: periodic, exponential, and
Bernoulli, for the two‐phase handoff protocol. The design objective is to determine the time to invoke path optimization such
that the average cost per connection is minimized. We develop a discrete time analytical model and a discrete‐event simulation
model for comparing the performance of the three path optimization schemes. Results indicate that the Bernoulli path optimization
scheme outperforms the other two schemes by providing a lower average cost per connection. The proposed models can also be
adapted to analyze other path optimization schemes in general.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
13.
Mobile radio networks based on ATM (asynchronous transfer mode) technology, such as wireless ATM, are considered. More precisely, the topology of connections between the ATM nodes and the base stations is investigated, taking the limited capacity of ATM nodes into account. This requires the partitioning of cells, that is, the set of cells has to be subdivided into subsets so that base stations of cells belonging to the same subset are connected to the same ATM switch. Among the possible partitions, the optimum solution is that giving the minimum number of handovers requiring a change of ATM switch: in this case, a path rerouting procedure must be carried out, causing additional delays in executing the handover. The optimum partition could be found by exhaustively considering all possibilities once the handover rates between cells is known; however, this would lead to an incredible complexity for the planning of large networks. We define a general methodology based on the concept, of “handover rate” between cells, which allows the choice of the best partition by taking mobility, radio, and fixed network aspects into account. Moreover, some new low-complexity partitioning algorithms determining suboptimum solutions are proposed. Finally, we show that the suboptimum partition slightly depends on some radio interface choices, such as the handover algorithm, thus allowing separate design of the two aspects 相似文献
14.
15.
Sivalingam Krishna M. Chen Jyh‐Cheng Agrawal Prathima Srivastava Mani B. 《Wireless Networks》2000,6(1):73-87
This paper describes the design and analysis of a low‐power medium access control (MAC) protocol for wireless/mobile ATM networks.
The protocol – denoted EC‐MAC (energy conserving medium access control) – is designed to support different traffic types with
quality‐of‐service (QoS) provisions. The network is based on the infrastructure model where a base station (BS) serves all
the mobiles currently in its cell. A reservation‐based approach is proposed, with appropriate scheduling of the requests from
the mobiles. This strategy is utilized to accomplish the dual goals of reduced energy consumption and quality of service provision
over wireless links. A priority round robin with dynamic reservation update and error compensation scheduling algorithm is
used to schedule the transmission requests of the mobiles. Discrete‐event simulation has been used to study the performance
of the protocol. A comparison of energy consumption of the EC‐MAC to a number of other protocols is provided. This comparison
indicates the EC‐MAC has, in general, better energy consumption characteristics. Performance analysis of the proposed protocol
with respect to different quality‐of‐service parameters using video, audio and data traffic models is provided.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
16.
Error correction and error detection techniques are often used in wireless transmission systems. The Asynchronous Transfer
Mode (ATM) employs Header Error Control (HEC). Since ATM specifications have been developed for high‐quality optical fiber
transmission systems, HEC has single‐bit error correction and multiple‐bit error detection capabilities. When HEC detects
multiple‐bit error, the cell is discarded. However, wireless ATM requires a more powerful Forward Error Correction (FEC) scheme
to improve the Bit Error Rate (BER) performance resulting in a reduction in the transmission power and antenna size. This
concatenation of wireless FEC and HEC of the ATM may effect cell loss performance. This paper proposes error correction and
error detection techniques suitable for wireless ATM and analyzes the performance of the proposed schemes.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
17.
Prathima Agrawal Eoin Hyden Paul Krzyzanowski Mani B. Srivastava John A. Trotter 《The Journal of VLSI Signal Processing》1996,13(2-3):87-104
The SWAN (Seamless Wireless ATM Network) system provides end-to-end ATM connectivity to mobile end-points equipped with RF transceivers for wireless access. Users carrying laptops and multimedia terminals can seamlessly access multimedia data over a backbone wired network while roaming among room-sized cells that are equipped with basestations. The research focus on how to make ATM mobile and wireless distinguishes SWAN from present day mobile-IP based wireless LANs. This paper describes the design and implementation of the ATM-based wireless last-hop, the primary components of which are the air-interface control, the medium access control, and the low-level ATM transport and signalling.The design is made interesting by its interplay with ATM; in particular, by the need to meaningfully extend over the wireless last-hop the service quality guarantees made by the higher level ATM layers. The implementation, on the other hand, is an example of hardware-software co-design and partitioning. A key component of the wireless hop implementation is a custom designed reconfigurable wireless adapter card called FAWN (Flexible Adapter for Wireless Networking) which is used at the mobiles as well as at the basestations. The functionality is partitioned three-way amongst dedicated reconfigurable hardware on FAWN, embedded firmware on FAWN, and device driver software on a host processor. Using an off-the-shelf 625 Kbps per channel radio, several of which can be supported by a single FAWN adapter to provide multiple channels, per-channel unidirectional TCP data throughput of 227 Kbps (or, 454 Kbps bidirectional) and per-channel unidirectional native ATM data throughput of 210 Kbps (or, 420 Kbps bidirectional) have been obtained. 相似文献
18.
Håkan Mitts Harri Hansén Jukka Immonen Simo Veikkolainen 《Mobile Networks and Applications》1996,1(3):299-312
Handover is one of the key research topics for the emerging wireless ATM networks. This paper describes a handover mechanism for intra-switch handovers for wireless ATM. The handover procedure is simple enough to be implementable as a limited enhancement to ATM switch platforms for fixed network, yet provides low delay and lossless handover when used together with a suitable radio interface. The paper also reports on initial simulation result. 相似文献
19.
A control and management network for wireless ATM systems 总被引:1,自引:0,他引:1
Bush Stephen F. Jagannath Sunil Sanchez Ricardo Evans Joseph B. Frost Victor S. Minden Gary J. Shanmugan K. Sam 《Wireless Networks》1997,3(4):1-17
This paper describes the design of a control and management network (orderwire) for a mobile wireless Asynchronous Transfer
Mode (ATM) network. This mobile wireless ATM network is part of the Rapidly Deployable Radio Network (RDRN). The orderwire
system consists of a packet radio network which overlays the mobile wireless ATM network. Each network element in this network
uses Global Positioning System (GPS) information to control a beamforming antenna subsystem which provides for spatial reuse.
This paper also proposes a novel Virtual Network Configuration (VNC) algorithm for predictive network configuration. A mobile
ATM Private Network–Network Interface (PNNI) based on VNC is also discussed. Finally, as a prelude to the system implementation,
results of a Maisie simulation of the orderwire system are discussed.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
20.
ATM via satellite: A framework and implementation 总被引:6,自引:0,他引:6
This paper describes an ATM‐based satellite network, focusing on the networking (ATM) aspects of the design. The ATM requirements
and the basic design of the network are outlined. In particular, a simple MAC layer is proposed in which ATM service classes
are mapped onto MF‐TDMA uplink access methods. The uplink access and resource allocation approaches based on this model are
described in detail. Also, this paper shows how different qualities‐of‐service can be provided by using a combination of different
access schemes. This paper also covers scheduling for the uplink portion of the satellite network. The use of Hierarchical
Round Robin is argued on the grounds of performance, flexibility and implementability.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献