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DIFFERENT MAC PROTOCOLS FOR NEXT GENERATION

WIRELESS ATM NETWORKS

Sami A. El-DolilDept. of Electronic and Electrical Comm. Eng., Faculty of Electronic Eng, Menoufya Univ.

[email protected]

ABSTRACTThis paper presents a comparison between three proposed Medium Access Control

(MAC) Protocols for next generation multimedia wireless ATM (WATM)networks. To support the ATM CBR, VBR, ABR services to end users, a MAC

protocol must be able to provide bandwidth on demand with suitable performanceguarantee. The protocols have been proposed to efficiently integrate multiple ATMtraffics over the wireless channel while achieving high channel utilization. Theobjective of the comparison is to highlight the merits and demerits of the three

proposed protocols.

Keywords: Medium access control protocol and ATM network.

1 INTRODUCTION

Asynchronous transfer mode (ATM) was

recommended by the InternationalTelecommunication Union (ITU-T) to be the transferprotocol of the broadband integrated services digitalnetwork (B-ISDN). The concept of wireless ATM(WATM) was introduced to extend the capabilities of

ATM to wireless arena in [1].A major issue of WATM network is the

selection of a medium access control (MAC)protocol that will efficiently allocate the scarce radioresources among the competing mobile stationswhile satisfying the QoS required for each admittedconnection.

Several MAC protocols are proposed forwireless ATM network [2] [9]. In [2], a novelpredictive approach is used to estimate the currentrequirements for the connections. The variable bitrate (VBR) traffic is divided into guaranteed andbest effort traffic while the time to expiry algorithm

is adapted for voice and VBR slot allocation. In [3],the leaky bucket algorithm with priority as well asthe cell train concept achieves a fair and efficientslot allocation. In [4], Packet Reservation MultipleAccess with Dynamic Allocation (PRMA/DA)MAC protocol adopts dynamic allocation algorithm

in order to resolve the contention situation quicklyand avoid the waste of bandwidth that occurs whenthere are several unneeded request slots. Howeverthe drawback is that this protocol does not use mini-slots for the access request. In [6] the use of piggybacking information from VBR connectionimproves the slot allocation for VBR traffic and

enhances the overall protocol performance.The current paper introduces a quantitative

comparison of three proposed MAC Protocol for

wireless ATM networks. The three protocols are as

follow.1. Dynamic Allocation TDMA MAC Protocol for

Wireless ATM Networks.2. An Intelligent MAC Protocol for next generation

Wireless ATM Networks.3. Contention and Polling based Multiple Access

Control with minimum Piggybacking for

Wireless ATM Network.Three performance metrics, namely cell lossprobability, average cell delay, and throughput, areconsidered. Section II gives an overview anddescription of the proposed protocols. In section III,the source models are identified. Section IV,describes the resource allocation algorithm. An

evaluation of the performance of the proposedprotocols is presented in section V. Finally, sectionVI concludes the paper.

2 SYSTEM DESCRIPTION

2.1 Air Interface Frame StructureThe proposed protocols use frequency division

duplex (FDD) with a fixed frame length of2 m sec. used for the uplink (UL) and the downlink

(DL) channel. Fig. 1 illustrates the frame structurefor the uplink channel. The channel bit rate is 4.9Mbps and the data slot size is 53 bytes. The numberof slots per frame is 24 slots. The uplink frame isdivided into control and data transmission periods,each consisting of integer number of slots. Slots

assigned for control purpose are further subdividedinto four control mini-slots with each mini-slot

accommodating reservation mini-packet.

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Control period Data Transmissionperiod

In the uplink channel, control slots provide acommunication mechanism for a mobile station to

send a reservation request during the contentionphase of the connection. The data slots are provided

with contention-free mechanism during the datatransmission phase. An uplink control packet is sentwhenever a mobile station needs to inform the basestation with its traffic characteristics and source

status.Feedback for the uplink control packets is sent in the

downlink control packets.

2.2 Contention Access SchemeThe first and second protocols use the same

contention scheme and the length of the control period is dynamically adjusted as a function of

contention traffic load. The control mini-slots areused by the mobile stations to send their reservationrequests in contention mode using slotted Aloha protocol. To reduce the access time of real-time

connection, which greatly affects the QoS of thereal-time services, we separate the control mini-slots

assigned to real-time and non real-time connections.

The number of control mini-slots assigned to real-time and non real-time connections is adaptivelyallocated with the collision status. The total numberof uplink control mini-slots ranges from 4 to 12

mini-slots. A priority is given to real-timeconnections by assigning their control mini-slotsfirst according to the number of collisions occurredin the previous frame.

In the third protocol, the control period is furtherdivided into contention and polling periods. Control

slots assigned in the control period are furthersubdivided into four control mini-slots, some of themused as contention mini-slots and the others used as

polling mini-slots. A fixed number of control mini-slots are allocated for contention and polling access.The contention mini-slots are used by voice

connections to send their reservation requests incontention mode at the beginning of talk-spurt, whilethe poling mini-slots are used by ABR connectionsto send their buffer length status to the base station.The number of polling mini-slots are chosen suchthat the polling period will be less than or equal to

the average inter-arrival time of ABR data message(100 m-sec).

Number of polling mini-slots int (number of ABR

users * (TF/Tint)).

Figure: 1 the frame structure.

where,

TF: Frame duration (2 m-sec).

Tint: Average inter-arrival time of ABR data message(100 m-sec).

Int: largest integer value.

Contention period is set to a constant number ofcontrol mini-slots and this number is chosen to

satisfy the required QoS for voice traffic. The

contention process is divided to four stages:

First Stage: When the connection becomes active it

randomly selects one of the 4subsequent frames to send its requestduring the contention period.

Second Stage: If the connection exhibits collision inthe first stage it randomly selects oneof the 3 subsequent frames to send itsrequest during the contention period.

Third Stage: If the connection exhibits collision inthe second stage it randomly selects

one of the 2 subsequent frames tosend its request during the contentionperiod.

Fourth Stage: If the connection exhibits collision inthe third stage it sends its request inevery frame until the base station

successfully receives its request.

In every stage the connection randomly select one ofthe available contention mini-slots in the selected

frame to send its reservation request. If theconnection request is correctly received during any

stage the connection exit from the contention process

and the base station periodically allocate slots to theconnection until the end of talk-spurt.

The described contention process aims to reduce thecontention load during the contention period in eachframe, increase the probability of successfullyaccessing the network, decreasing the probability ofcollision, reduce the access delay time and at thesame time minimize the number of used contention

mini-slots and utilize them efficiently. Decreasingthe number of available frames for selection in eachsubsequent stage aiming to reduce the access delaytime of the connections and hence reduce the cell

loss probability.


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2.3 Traffic Integration Strategy

As different wireless ATM services share the

same resources, an effective interaction between theallocation algorithms is needed to maximize theutilization efficiency of the shared resources. In thefirst and second protocol , the voice connections

have the highest priority and the VBR connectionshave the next higher priority. The ABR connections

have the lowest priority.In the third protocol, the available transmission

slots are assigned first to active voice connections,then a minimum assigned slots are allocated to ABRtraffic, then VBR traffic slots are allocated, andfinally, the remaining slots are distributed between

ABR connections according to the buffer length ofeach connections.

3 SOURCE MODELS

3.1 Voice Source ModelA voice source generates a signal that follows a

pattern of talk-spurts separated by silent gaps. A

speech activity detector can be used to detect thispattern. Therefore, an ON/OFF model can describe avoice source: the source alternates between the ONstate where the source generates packets at rate 8

kbps, and the OFF state where no packets aregenerated. Durations of talk-spurts and silent gaps

are modelled as exponential distributions with meanvalues of 1 and 1.35 sec, respectively.

If a voice packet is not sent within its maximumtransfer delay (MTD), it should be dropped TheMTD is set to be 16 m-sec.

3.2 VBR Source ModelThe source rates are modelled as truncated

Gaussian distribution between (128 384 kbps)with mean rate of 256 kbps. The rate of the sourcevaries every 33 m-sec (the duration of image frame)and the MTD of the VBR packet is set to be 50 m-

sec.

3.3 ABR Source ModelIt resembles a data source with messages of

certain length. The length of the message isexponentially distributed with mean 2 k bit, and the

inter-arrival time between messages is negativelyexponential distributed with mean of 100 m-sec.The MTD of the ABR packet is set to be 6 sec.

4 BANDWIDTH ALLOCATION ALGORITHM

The bandwidth allocation for uplinktransmission is only considered since the downlinktransmission can be scheduled in the same manneras in a wired ATM switch.

4.1 Dynamic Allocation TDMA MAC Protocol for

Wireless ATM Networks4.1.1 Slot Allocation Algorithm for VoicetrafficThe voice connections have the higher priority.

At the beginning of a talk-spurt, the mobile sends a

control packet. When the base station knows that theconnection becomes active the base station periodically allocates slots to the connection untilthe end of talk spurt. At the end of the talk-spurt, themobile sets a flag in the last voice packet to inform

the base station that the connection is no longeractive.

4.1.2 Slot Allocation Algorithm for VBR trafficVBR connections have the next highest priority.

They only contend (send a control packet) at thesession beginning. Next, all the control information

is piggybacking on the data packets, which reducesthe contention over the real-time mini-slots. At the

base station, a token pool of certain size isintroduced for each VBR connection. Tokens aregenerated at a fixed rate that is equal to the meancell rate. A token is removed from the

corresponding pool for every slot allocated to theconnection

After slot allocation for voice connections the basestation allocates one slot for each VBR connectionto send one of their cells and also to piggyback thecurrent traffic parameter (e.g. buffer length, cell

delay) of the connection. Then the base stationallocates slots for each connection .The number of

slots allocated for a connection is the minimum of

the buffer length and the number of tokens in thepool such as;

Nv= min (Av, Bv) .

whereNv : number of slots allocated for the VBR

connection.Av : number of tokens in the pool.Bv : number of the packets in the mobile

station buffer.

Each connection cannot send greater than 12 cells inthe frame. Within the frame, priority is given to theconnection with minimum time-of-expiry to send

their cells earlier.4.1.3 Slot Allocation Algorithm for ABR traffic

The base station records the buffer length

status of each connection using the controlinformation transmitted by the mobile. When amessage arrives at a mobile, it sends the number ofpackets in the new message either piggybacked to adata packet or in a control packet.Like VBR connections a token pool is introduced

for each ABR connection. ABR connections havelower priority than voice and VBR connections. The

number of slots allocated for a connection is theminimum of the buffer length and the number of

tokens in the pool such as;


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Na= min (Aa , Ba).where,

Na : number of slots allocated for the ABRconnection.

Aa : number of tokens in the pool.

Ba : number of the packets in the mobile

station buffer.The connection with higher number of tokens in

its pool sends their cells earlier within the frame. Ifthere are remaining slots inside the frame, the basestation allocates them fairly between ABR and VBR

connections.

4.2 An Intelligent MAC Protocol for next

generation Wireless ATM Networks4.2.1 Slot Allocation Algorithm for Voice andCBR traffic

The voice connections have the highestpriority. At the beginning of a talk-spurt, the mobile

sends a control packet to inform the base station thatthe connection become active.At the base station, a token pool is introduced foreach active voice connection and each token is

increased by a fixed amount equal to Tv every frameto indicate the number of cells generated in the

mobile station buffer and decreased by one for everyslot allocated to the corresponding connection. Thenthe voice connections are arranged according to thecontent of its token and slots are allocated to the

connection with higher value in its token first. Atthe end of the talk-spurt, the mobile sets a flag in the

last voice cell to inform the base station that the

connection is no longer active.Tv=Tf /Tpwhere,

Tf : frame duration (2msec).

Tp : packetization time of the ATM cell ofvoice connection (48m-sec).The number of slots allocated for voice connectionin each frame should not exceed Lv .whereLv = number of voice connection*( Tf / Tp).

The token poll has two advantages:First: it indicates the number of packets

generated at the mobile station buffer.Second: it indicates the amount of delay of the

generated packet.

This helps in deciding which voice connectionshould send its packet early and leads to reducingthe average delay of the voice connections.

4.2.2 Slot Allocation Algorithm for VBR trafficVBR connections have the next higher priority.

They only contend (send a control packet) at thesession beginning. Next, all the control information

is piggybacking on the data packets, which reducesthe contention over the real-time mini-slots. At the

base station, one token pool of certain size is

introduced for all VBR connections. Tokens aregenerated at a fixed rate that is equal to the meancell rate per connection multiplied by the number ofVBR connections. A token is removed from thecorresponding pool for every slot allocated to any

VBR connection. The cell delay is piggybacking on

the data packets.The number of slots allocated for a VBR connectiondepends on the cell delay and the number of tokenin the pool such as;Nvj=int ( Kv* ( Dvj/Dv))

whereNvj : number of slots allocated for the

connection number jKv : number of tokens in the poolDvj : delay time of the last transmitted cellfrom connection number j

Dv : total cell delay of all VBR connections

4.2.3 Slot Allocation Algorithm for ABR trafficThe base station records the buffer length status

of each connection using the control informationtransmitted by the mobile. When a message arrives

at a mobile, it sends the number of packets in thenew message either piggybacked to a data packet or

in a control packet.Like VBR connections one token pool is introducedfor all ABR connections. ABR connections havelower priority than voice and VBR connections. The

number of slots allocated for an ABR connectiondepends on the buffer length and the number of

token in the pool such as;

Naj= Ka* ( Baj/Ba)Where

Naj : number of slots allocated for theconnection number j.

Ka : number of tokens in the pool.Baj : number of cells in the buffer of the

connection (buffer length).Ba : summation of the buffer lengths of all

ABR connections.If there are remaining slots inside the frame, the

base station allocates them between ABR and VBRconnections such that % for VBR connections andthe rest for ABR connections where;

= (

oe

avg

T

D)*100.

whereDavg : average delay of VBR connections.Toe : time of expiry of VBR cells (50 m-sec).

4.3 Contention and Polling based Multiple Access

Control with minimum Piggybacking for

Wireless ATM Network4.3.1 Slot Allocation Algorithm for Voice Traffic

At the beginning of talk spurt the voice

connection sends a reservation request through the


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contention mini-slot. When the base stationsuccessfully receives the request, it periodicallyallocates slots to the connection up to the end of talkspurt. At the end of talk spurt the connection set aone bit flag in the last transmitted cell to indicate that

the connection is no longer active.

4.3.2 Slot Allocation Algorithm for VBR Traffic

Initially the base station allocates one slot foreach active VBR connection and then broadcast adelay threshold value to all VBR connections everyframe. One bit flag is used to indicate the delay

status of the buffer and is piggybacked to the datapacket (cell). Each VBR connection checks its buffer

and sets the flag to one when the packet delayexceeds the delay threshold, and to zero when thepacket delay is lower than the delay threshold. Theslot allocation procedures are performed as follow:

The base station increases the assigned slots by onefor a VBR connection each time its

packet delay is greater than the delay threshold(piggybacking flag equal to one).

At the base station a counter is introduced. The

counter incremented by one when the number ofslots allocated for VBR traffic in the frame is greaterthan Vmean and decremented by one when it is lowerthan Vmean.

where; Vmean: the mean number of cellsgenerated from all VBR connections perframe according to the mean cell generation

rate per connection.

The delay threshold can be set to a fixed value ordynamically adjusted to control the slot allocationprocess for VBR traffic. The counter can be used todynamically adjust the delay threshold by increasing

the delay threshold value when the counter value isincreased and decreasing the delay threshold valuewhen the counter is decreased. Since the increase inthe counter value indicates the increase in theallocated bandwidth (slots), so we need to reduce it byincreasing the delay threshold value which in turn

decreases the piggybacking and hence decreases the

number of allocated slots and vice versa. Table.1shows the dynamic delay threshold values using thedynamic adjustment.

When some of the connection reserved slots are notused by the connection for transmitting its packets(number of generated packets become lower than thenumber of allocated slots) the base station release thisslot and decrement the number of the reserved slots

for that connection in the subsequent frames by one.

When the counter becomes greater than the upperlimit value (25) the base station release some of thereserved slots for the connections that have no

piggybacking in the previous frame until the number

of VBR allocated slots becomes lower than Vmean todecrease the counter.

Each VBR connection could not havelower than one allocated slot per frame.

As we suggested before the delay threshold can

be set at a fixed value and its value have a significanteffect on the allocation process and the achievedQoS of VBR traffic. During the simulation at fixeddelay threshold we take its fixed value equals to 0.5maximum CTD of VBR cell (25msec) as anappropriate value and evaluate the performance of

the allocation process in this case.

Table 1: Dynamic adjustment of the delay threshold

Counter Delay Threshold values

(m-sec)

Counter4 154 < counter 8 20

8 < counter12 25

12 < counter15 30

15 < counter18 35

18 < counter 20 40

20 < counter 45

4.3.3 Slot Allocation Algorithm for ABR Traffic

Polling control mini-slots are used by ABRconnections to send their buffer length to the base

station. The number of polling mini-slots is selectedsuch that the polling period should be lower than orequal to the inter-arrival time between ABR datamessages (100 m-sec) to enable the base station toefficiently monitor the buffer length status of eachconnection.

Initially a minimum number of slots are allocatedto ABR traffic. So that, each ABR connection has anallocated bandwidth equivalent to 50 % of its

average cell generation rate. The base station

controls this minimum assigned bandwidth bymaintaining a leaky bucket for every ABRconnection. Tokens added to the bucket at constantrate equals to 50% of the average cell generation rate.Every time a slot is allocated to the connection, a

token is removed from the bucket. So, in each framethe connection with non empty leaky bucket has

allocated slots equal to the number of tokens in its bucket. After allocating the VBR traffic slots, theremaining slots are allocated to ABR connections.ABR connections are arranged according to their

buffer length where the connection with higherbuffer length has its required slots allocated first.


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5 PERFORMANCE EVALUATION AND

SIMULATION RESULTSA comparison has been made to evaluate the

performance of the three proposed protocols using thesame simulation parameters.

Fig. 2 through Fig. 7 illustrates the performance

with integrated traffic. There are 30 voiceconnection and 12 VBR connections in the network,while the ABR connections are added gradually tothe network. All results are presented as a functionof the number of ABR connection.

For voice traffic, Fig. 2 and Fig. 5 show that agood QoS is achieved by the three protocols in term of

cell loss probability (lower than 10-4

) and average celldelay (lower than 5 m-sec). it is clear that,approximately, the first and the second proposedprotocols achieve better performance than the third one

as they use the same contention access scheme, due tousing lower number of control mini-slots for

contention access. It is worth to mention that the thirdprotocol uses 8.3% of the bandwidth (8 control mini-slots) for contention and polling access, while the firstand second protocol uses 4.45% of the bandwidth

(approximately 4 control mini-slots) which make theavailable data transmission bandwidth for the third

protocol lower by 3.85 % than that of the first andsecond protocol.

For VBR traffic, Fig. 3 shows that with low VBRtraffic up to 45 connections, the second protocol

achieves the best performance in term of cell lossprobability as its resource allocation algorithm depends

on the cell delay at each connection buffer, so that the

connection with higher delay allocated more slots thanthat with lower delay which leads to reduce the probability that the cell delay exceeds the maximumCTD (cell transfer delay) and then lost. This decreases

the cell loss probability. On the other hand thisincreases the average cell delay that becomes higherthan the average cell delay caused by the first protocolas indicated in Fig. 6.The third protocol achieveshigher loss probability than the second protocol (Fig.3), and the highest average cell delay (Fig. 6) since the

dynamic delay threshold adjustment process producesmore average delay than the other two protocols. Whenthe number of ABR connections becomes greater than

45, the offered traffic becomes higher than theavailable bandwidth. The third protocol achieves thelowest cell loss probability and lower average cell

delay than the second one since a considerable part ofABR slot allocation takes place after VBR slotallocation, and the VBR slot allocation is controlled bythe value of delay threshold which has upper limitvalue. So increasing the number of ABR connectionhas low significant effect on VBR slot allocation. The

first protocol achieves the lowest performance in termsof cell loss probability (Fig. 3), while achieves the

lowest average cell delay with all number of ABRconnections, (Fig. 6). This indicates that the efficiency

of its VBR Resource allocation algorithm is lower thanthe other two protocols.

For ABR traffic, Fig. 4 and Fig. 7 show that thereduction of data transmission bandwidth of the third protocol by 3.85% due to the contention and polling

periods significantly reduces the available bandwidth

for ABR traffic which make the cell losses start earlybefore 40 ABR connection and the average cell delaysignificantly increases with ABR connections since aconsiderable part of ABR resource allocations takesplace after VBR slot allocation. The first and second

protocols achieve good QoS for ABR traffic but thefirst protocol achieve slightly better performance in

term of cell loss probability and average cell delay.At 45 ABR connection the first and second

protocol achieve approximately 94% data transmissionthroughput and 98.5% total channel utilization while

providing the acceptable QoS required for each trafficcategory. For the third protocol, at 36 ABR connection

91% data transmission throughput and 98.5% totalchannel utilization are achieved while preserving therequired QoS for each ATM traffic type.

Figure 2: Cell loss probability of Voice connectionsas a function of the number of ABR connections (12VBR and 30 Voice connection)

Figure 3: Cell loss probability of VBR connections as a function of

the number of ABR connections (12 VBR and 30 Voice connection)


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The performance with real time traffic is illustrated inFig. 8 through Fig. 11. 12 VBR connections are presented while the voice connections are addedgradually to the system. For voice traffic, Fig. 8 andFig. 10 show that the performance is the same as with

integrated traffic, where the first and second protocols

perform better than the third one. For VBR traffic, Fig.9 and Fig. 11 show that the second protocol achievesthe lowest cell loss probability. The average cell delayof the first and second protocols is low with slightlydifferent values until 112 voice connection (97%

channel utilization), after that, the average cell delay ofthe second protocol become significantly higher since

the efficiency of its resource allocation algorithm inreducing cell loss probability results in increasing theaverage cell delay. The third protocol has lower celldelay than that with integrated traffic because in the

absence of ABR traffic, any remaining slots will begiven to VBR connections.

With the third protocol the average cell delay lowerthan with integrated traffic because in the absence ofABR traffic if there are remaining slots they will begiven to VBR connections.

A cell loss probability of 10-3 for VBR traffic

achieved by the first protocol at 106 voice connection

(95% channel utilization), by the second protocol at112 voice connection (97% channel utilization), and bythe third protocol at 103 voice connection (94.7%channel utilization).

Figure 6: Average cell delay of VBR connections as afunction of the number of ABR connections (12 VBR

and 30 Voice connections).

Figure 4: Cell loss probability of ABR connections as afunction of the number of ABR connections (12 VBRand 30 Voice connection)

Figure 7: Average cell delay of ABR connections as afunction of the number of ABR connections (12 VBRand 30 Voice connections).

Figure 5: Average cell delay of Voice connections as afunction of the number of ABR connections, (12 VBRand 30 Voice connections).


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These results indicate that the second protocol has themost efficient VBR slot allocation algorithm then thefirst protocol and finally the third protocol, but thethird protocol uses the lowest piggybacking overhead.

6 CONCLUSION

We have presented an extensive performancecomparison of three proposed MAC protocols tohighlight the merits and demerits of each of them.

For voice traffic, a good QoS achieved by the three protocols. But, the first and second proposed

protocols achieve better QoS than the third protocolwhile using lower number of control mini-slots forcontention access. For VBR traffic, the resultsindicate that the second protocol has the most

efficient VBR slot allocation algorithm then the firstprotocol and finally the third protocol, but the third

protocol uses the lowest piggybacking overhead. ForABR traffic, the reduction of data transmissionbandwidth of the third protocol by 3.85% reduce theavailable bandwidth for ABR traffic which make thecell losses and the average cell delay significantly

increases with higher values than the other two

protocol. Finally the three proposed protocolsachieve very high channel utilization ofapproximately 98% for the wireless ATM channelwhile respects the required QoS of multimedia ATMtraffic types.

Figure 8: Cell loss probability of Voice connections asa function of the number of Voice connections (12 VBRConnection).

Figure 10: Average cell delay of Voice connections asfunction of the number of voice connections (12 VB

connections).

Figure 9: Cell loss probability of VBR connections as afunction of the number of Voice connections (12 VBRConnection).

Figure 11: Average cell delay of VBR connections asfunction of the number of voice connections (12 VB

connection)


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REFERENCES

[1] D. Raychandhuri and N. D. Wilson, ATM

based transport architecture for multi-services wireless personal communicationnetworks IEEE J. Selected. Areas inCommunication, vol.12, no.80, pp. 1401-

1414, Oct. 1994.

[2] J.F. Frigon, H.C.B.Chan and V.C.M. leungDynamic reservation TDMA protocol forwireless ATM networks IEEE J. SelectedAreas in Communication, vol.19, no.2, pp370-383, Feb.2001.

[3] N.Passas, S. Paskalis, D.Vali and L.MerakosQuality-of -Service Oriented Medium AccessControl for wireless ATM networks IEEECommunication Magazine, pp. 42-50, 1997.

[4] J.Sanchez, R. Martnez, and M.W.Marcellin Asurvey of MAC Protocols Proposed forWireless ATM IEEE Networks, pp. 52-62,

Nov. 1997.

[5] H. Liu, U. Cliese and L. Dittmann Knowledge-based Multiple AccessProtocol in Broadband Wireless ATM Networks 50 th Veh. Tech. Conf., pp.

1685-1689, Sept. 1999 . Amesterdam, theNtherlands.

[6] S. Lee, Y. Song , D. Cho , Y. Dhong and J.Yang

Wireless ATM MAC layer Protocol for NearOptimal Quality of Service Support GLOBECOM. 98 Sydney, Australia, pp. 2264-2269, Nov.1998 .

[7] Y.Kwork and K.N.Lau A quantitativeComparison of Multiple Access Control Protocolsfor Wireless ATM IEEE Transaction onVehicular Technology, vol.50, no.3, MAY 2001.

[8] R. Steele and L. Hanzo, Mobile RadioCommunications, Wiley and Sons, NewYork, 1999.

[9] J. C.Chen , K.M.Sivalingam and R.Acharya

Comparative Analysis of Wireless ATM ChannelAccess Protocols Baltzer Journals, Sept. 1997.

[10] Sami A. EL-Dolil and Mohammed Abd Elnaby" Dynamic Allocation TDMA MAC Protocolfor Wireless ATM Networks" Proc. of theTwentieth National Radio Science Conference

(20th NRSC 2003), March 18-20, Cairo,Egypt.

[11] Sami A. EL-Dolil and Mohammed Abd Elnaby" An Intelligent Resource ManagementStrategy for Next Generation WATM PersonalCommunication Network," The Proc. of the

46th

IEEE International Midwest Symposium

On Circuits & Systems (The 46th

IEEE

International MWSCAS), December 2003,Cairo, Egypt.

[12] Sami A. EL-Dolil and Mohammed Abd Elnaby" Contention and Polling Based Multiple

Access Control with Minimum Piggybacking

for Wireless ATM Networks, " 21st

NationalRadio Science Conference (21st NRSC 2004),March 16-18, Cairo, Egypt.


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