Dynamic slot allocation multiple access protocol for wireless ATM networks

An enhanced multiple access scheme is presented for wireless ATM networks. The DSAMA (dynamic slot allocation multiple access), which was proposed by Wu et al. (see ICC97, p.1560-65, 1997), is a combination of reservation multiple access protocol and dynamic slot allocation algorithm. The slot utilization in DSAMA is higher than other existing integrated services multiple access, e.g. PRMA, etc. However, in DSAMA, it uses an orthogonal code for reservation, and the application of this orthogonal code strongly depends on the speed of a special chip, which is used to generate the orthogonal code. It requires the speed of this chip to be equal to the channel rate. Unfortunately, this will limit the application range of this MAC scheme. We present a new reservation method from a more general point of view, which makes the MAC protocol free from the hardware. By using an orthogonal address code and a new RR slot, the collision rate of the W-cell is reduced to a very low level. In addition, due to the limitation of the bandwidth available in the wireless network, we propose a more effective dynamic slot allocation algorithm. With a more exact boundary variable and a new allocation mechanism, we obtain a higher statistical multiplexing gain.

As the battle environment becomes more complicated, the demand for higher accuracy and better anti-jam capacity of navigation has been increasing. The conventional JTIDS/INS/GPS integrated navigation cannot meet the demands of certain situations such as precision strike and formation flight. A new system that introduces the differential GPS into JTIDS/INS/GPS integration system is proposed to improve the navigation performance in the modern combined operations. In this system, the differential information of DGPS is transmitted through the communication data link of Link-16. As a result, the system resources are efficiently utilized and the controllability and anti-jam performance of the system are significantly enhanced. A hybrid slot allocation protocol (HSAP) that combines a static slot allocation algorithm and a dynamic slot allocation algorithm and the corresponding source-chosen mechanisms are proposed. The performance of the JTIDS/INS/GPS integration navigation using the differential GPS information from one or multiple base stations is studied and compared with that of the system without using the differential GPS information. Furthermore, the performance of the integration navigation using HSAP is compared with that of the system using static slot allocation algorithm. We show that navigation accuracy based on the differential GPS is improved, and using HSAP also leads to higher localization accuracy.

The High Band Radio network has extensive value in the military application. A Dynamic Slot Allocation Algorithm (DSA) based on the High Band Radio network TDMA protocol is proposed in this paper, DSA algorithm allocates slots dynamically according to the difference of network traffics. The simulation results show that DSA algorithm can sustain TDMA protocol improving the network characters according to the difference of the network traffics.

Two major challenges pertaining to wireless asynchronous transfer mode (ATM) networks are the design of multiple access control (MAC), and dynamic bandwidth allocation. While the former draws more attention, the latter has been considered nontrivial and remains mostly unresolved. We propose a new intelligent multiple access control system (IMACS) which includes a versatile MAC scheme augmented with dynamic bandwidth allocation, for wireless ATM networks. IMACS supports four types of traffic-CBR, VBR, ABR, and signaling control (SCR). It aims to efficiently satisfy their diverse quality-of-service (QoS) requirements while retaining maximal network throughput. IMACS is composed of three components: multiple access controller (MACER), traffic estimator/predictor (TEP), and intelligent bandwidth allocator (IBA). MACER employs a hybrid-mode TDMA scheme, in which its contention access is based on a new dynamic-tree-splitting (DTS) collision resolution algorithm parameterized by an optimal splitting depth (SD). TEP performs periodic estimation and on-line prediction of ABR self-similar traffic characteristics based on wavelet analysis and a neural-fuzzy technique. IBA is responsible for static bandwidth allocation for CBR/VBR traffic following a closed-form formula. In cooperation with TEP, IBA governs dynamic bandwidth allocation for ABR/SCR traffic through determining the optimal SD. The optimal SDs under various traffic conditions are postulated via experimental results, and then off-line constructed using a back propagation neural network (BPNN), being used on-line by IBA. Consequently, with dynamic bandwidth allocation, IMACS offers various QoS guarantees and maximizes network throughput irrelevant to traffic variation.

Wireless communications along with portable computers, digital assistants and sensor devices provide a pervasive base for mobile computing. However realizing truly ubiquitous mobile computing requires innovative theories, paradigms and applications in various research areas including algorithms, networking, software architectures and data management. Topic 14 covers all such aspects. This topic attracted 33 submissions showing the increasing interest in the field. From the submitted papers, 8 were accepted as full papers (24% acceptance rate). The selected papers cover various aspects of mobile and ubiquitous computing highlighting the diversity of the field and thus making up an interesting and stimulating track.Paper presentations are divided into three sessions. Two papers in the first session address consistency issues. In “Efficient and Fault-Tolerant Update Commitment for Weakly Connected Replication”, J. Barreto and P. Ferreira propose a novel epidemic weighted voting protocol for achieving eventual consistency in optimistic replication that allows multiple update candidates in an election. In “Controlling Concurrency in Mobile Computing Environments with Broadcast-based Dissemination”, J. M. Monteiro and A. Brayner present a new serializability-based protocol for ensuring data consistency and currency when data are disseminated to clients through wireless broadcast. The last paper in this session, “Integrating Mobile Devices into the Grid: Design Considerations and Evaluation” by S. Isaiadis and V. Getov, discusses implementation and performance issues for integrating mobile devices into the grid. The second session is shared with Topic 8. The two papers address aspects related to frequency utilization in wireless networking. In “New Bounds on the Competitiveness of Randomized Online Call Control in Cellular Networks”, I. Karagiannis, C. Kaklamanis and E. Papaioannou present new upper and lower bounds for the online version of the call control problem in wireless cellular networks. In “A Multiple Channel Access Protocol for Ad Hoc Wireless Networks”, K-W. Jang considers the problem of enhancing channel utilization in wireless ad hoc networks through channel exchange between neighboring nodes. In the last session, in “Personalized Access to Semantic Web Agents Using Smart Cards”, R. C. Erdur and G. Kardas argue for storing personal information on smart cards. The other two papers focus on secure networking. K. Kim, J. Hong and J. Lim present a “Fast and Secure Communication Resume Protocol” to speed up connection resume after a communication error. In “On AAA with Extended IDK in Mobile IP Networks”, H. Jeon, M. Y. Chung and H. Choo discuss how to attain fast and secure mobile IP networking by addressing problems of the hand-off process in a secure way.

This paper presents a dynamic anchor scheme in wireless ATM (asynchronous transfer mode) networks, which improves the location registers (LR) scheme, in which LR’s are hierarchically structured. This dynamic anchor scheme introduces the CCR (communication-to-computation cost ratio) term in the LR scheme. The proposed scheme reduces computation cost by introducing the active LR. There are at most two active LR’s in a hierarchical arrangement of LR’s and the location of one active LR is static and the location of another active LR called as anchor LR is dynamically selected among the LRs in the hierarchy in order to minimize a total location management cost. The total location management cost is calculated depending on the CCR as well as the CMR (call-to-move ratio). Numerical results show that the proposed scheme can reduce the location management cost compared with the original LR scheme for the different values of the CCR and the CMR.KeywordsWireless ATMLocation Managementanchor scheme

This paper describes the design and performance of a new ATM adaptation layer protocol lAALdTr 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 AALdT is based on a novel and reliable ARQ mechanism to support qualitydcritical 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 AALdT provides higher throughput for TCP over wireless ATM networks compared to the existing approach of TCP with AAL 5.

The world of wireless telecommunications is rapidly changing. The capabilities of wireless networks are improving at a steady pace. This paper presents two possible protocols for implementing mobility for wireless users in an asynchronous transfer mode (ATM) network. The vision of the authors is of one "wireless ATM telecommunications network" that is capable of supporting a variety of today's applications with room to grow for advanced applications of the future. We first visit database architectures that can support mobility in a wireless ATM network. We then discuss one of two signaling architecture alternatives, the "overlay signaling," for overlay support of mobile users in the ATM-based wireless telecommunications network. "Overlay signaling" aims at minimizing the modification needed to the existing ATM protocols. We then describe a native "migratory signaling" approach that further integrates wireless and wireline users into one global wireless ATM network at the expense of requiring some modifications to the existing ATM protocols. A performance analysis of the proposed signaling architecture alternatives is also presented. We conclude by pointing out some challenges in merging ATM with wireless telecommunications.

This paper presents call admission control issues for an ATM-based wireless network with mobile hosts. Such wireless ATM networks are motivated by both an increasing demand for mobile capability for future broadband networks and broadband multimedia services for mobile systems. An ATM compatible wireless network capable of supporting a mix of broadband ISDN services is discussed. We present a conceptual view of a wireless ATM architecture with distributed call admission functions. Related issues of call admission control caused by these characteristics are discussed, and new trends toward call admission control in future wireless ATM network are identified.

Potential game and no-regret learning game based on game theory model of cognitive radio have been analyzed. According to these algorithms, the mathematic model of advanced dynamic spectrum allocation algorithm based on potential game has been brought forward. Finally, the simulations of these algorithms have been proved that advanced dynamic spectrum allocation algorithm based on potential game has the best capacity performance. However, how to reduce the allocation cost when allocating spectrum is also a considerable problem.

Traditional Time Division Multiple Access (TDMA) protocol provides deterministic periodic collision-free data transmissions. However, TDMA lacks flexibility and exhibits low efficiency in dynamic environments such as wireless LANs. On the other hand, contention-based MAC protocols such as the IEEE 802.11 DCF are adaptive to network dynamics but are generally inefficient in heavily loaded or large networks. To take advantage of the both types of protocols, a D-CVDMA protocol is proposed. It is based on the k-round elimination contention (k-EC) scheme, which provides fast contention resolution for Wireless LANs. D--CVDMA uses a contention mechanism to achieve TDMA-like collision-free data transmissions, which does not need to reserve time slots for forthcoming transmissions. These features make the D-CVDMA robust and adaptive to network dynamics such as node leaving and joining, changes in packet size and arrival rate, which, in turn, make it suitable for the delivery of hybrid traffic including multimedia and data content. D-CVDMA is designed for single-hop wireless ad hoc networks. Analyses and simulations demonstrate that D-CVDMA outperforms the IEEE 802.11 DCF and k-EC in terms of network throughput, delay, jitter, and fairness.

A multiple access protocol is a scheme to control the access to a shared communication medium (radio frequency) among various users. Although many access protocols have been proposed and each has its advantages and limitations, very few are suitable for integrated wireless communications. Access protocols can be grouped according to the bandwidth allocation mechanism, which can be static or dynamic, and according to the type of control mechanism implemented. Multiple access protocols can be categorized into three classes: fixed assignment, random assignment, and demand assignment.

Duty-cycling technique has been widely adopted in MAC protocols for wireless sensor networks to conserve energy. However, low duty-cycle also leads to limited throughput in most of existing solutions. In this paper, we propose iQueue-MAC to provide immediate yet energy-efficient throughput enhancement for dealing with burst or heavy traffic. Combined with CSMA/CA, iQueue-MAC makes use of queue length of each sensor node and allocates suitable TDMA slots to them for packets transmission. During light traffic period, no extra slots will be allocated; iQueue-MAC acts like other low duty-cycle MACs to conserve power. While in burst or heavy traffic period, iQueue-MAC senses the build up of packet queues and dynamically schedules adequate number of slots for packet transmission. We have implemented iQueue-MAC on STM32W108 chips that offer IEEE 802.15.4 standard communication. We set up several real-world experimental scenarios, including a 46 nodes multi-hop test-bed for simulating a general application, and conducted numerous experiments to evaluate iQueue-MAC, in comparison with other traffic adaptive duty-cycle protocols, such as multi-channel version RI-MAC and CoSenS. Results clearly show that iQueue-MAC outperforms multi-channel version of RI-MAC and CoSenS in terms of packet delay and throughput.

Constrained by the interior properties of underwater acoustic channels such as limited bandwidth, time-varying multipath propagation, and large propagation delay, the design of multiple access (MAC) protocols for underwater acoustic sensor networks (UWSN) poses significant challenges. Existing MAC protocols for UWSNs exhibit very low performance in channel utilization, throughput and end-to-end delay, as well as energy consumption since 1) they are based on the conventional stop-and-wait (SW) transmission scheme, and 2) fewer has error-control mechanism at the data link layer. In this paper, we assume the UWSN has a multi-hop flat topology, where there exist a sink node and some other common sensor nodes; all the nodes adopt Time Division Multiple Access (TDMA) to access channel. First, we classify all the nodes into different groups according to the numbers of hops between these nodes themselves and the sink node; the nodes belonging to different groups adopt TDMA frames with different starting time. We then propose a new MAC protocol by incorporating the multi-channel technique and the juggling-like stop-and-wait (JSW) transmission scheme (which was tailored for underwater acoustic communications), which is called the JB-MAC. Finally, simulation results are presented to highlight its good performance in terms of channel utilization, throughput and delay.

The unifying slot assignment protocol (USAP) multiple broadcast access (MBA) is a wireless, multichannel, TDMA protocol built on the USAP multiple access (MA) techniques presented at Milcoms 99 and 96 for establishing and maintaining an adaptive broadcast channel. The USAP MA transmitter-directed broadcast (TDB) uses distance-2 vertex coloring of the network graph to provide contention-free transmissions and allow reuse of any slot after 2 RF hops. In this paper these techniques are supplemented with receiver directed broadcast (RDB). The advantages include increased throughput for unicast traffic and the ability to efficiently manage a large number of channels. Application of the protocol to the Rockwell Collins Soldier Phone is presented.