Proceedings of the 6th WSEAS International Conference on Applied Informatics and Communications, Elounda, Greece, August 18-20, 2006 (pp65-73)
An Adaptable MAC Protocol in MANETs : A Democratic Approach
P.K.Srinivasan and Pallapa Venkataram∗
Protocol Engineering and Technology Unit,
Electrical Communication Engineering,
Indian Institute of Science, Bangalore-560 012, India
E-mail:{pks, pallapa}@ece.iisc.ernet.in
Abstract
Mobile ad-hoc networks (MANETs) have recently drawn significant research attention since they offer unique
benefits and versatility with respect to bandwidth spatial reuse, intrinsic fault tolerance, and low-cost rapid deployment.
This paper addresses the issue of delay sensitive realtime data transport in these type of networks. An effective QoS
mechanism is thereby required for the speedy transport of the realtime data. QoS issue in MANET is an open-end
problem. Various QoS measures are incorporated in the upperlayers of the network, but a few techniques addresses
QoS techniques in the MAC layer. There are quite a few QoS techniques in the MAC layer for the infrastructure based
wireless network. The goal and the challenge is to achieve a QoS delivery and a priority access to the real time traffic
in adhoc wireless environment, while maintaining democracy in the resource allocation. We propose a MAC layer
protocol called ”FCP based FAMA protocol”, which allocates the channel resources to the needy in a more democratic
way, by examining the requirements, malicious behavior and genuineness of the request. We have simulated both the
FAMA as well as FCP based FAMA and tested in various MANET conditions. Simulated results have clearly shown
a performance improvement in the channel utilization and a decrease in the delay parameters in the later case. Our
new protocol outperforms the other QoS aware MAC layer protocols.
Key-Words
1
: QoS, FAMA, FCP, Priority, node, MANET.
Introduction
that is shared by all the nodes that are in the same
radio communication range,and the radio frequency
bandwidth is limited. The packet collisions are unavoidable due to the fact that traffic arrivals are random and there is non zero propagation time between
transmitters and receivers. Therefore medium access
control protocols are used to co ordinate access to
the single channel in the network. Ad hoc networks
being decentralized various QoS measures has to be
implemented in order to support the Multimedia/real
time data. Many of MAC layers protocols have been
developed for the wireless ad hoc networks concentrates on enhancement of throughput and they do
not support the Multimedia applications. Sufficient
QOS parameters has to be specified for supporting
the real time data. The QoS parameters specified for
the multimedia wireless networks is not sufficient for
A MANET (Mobile Ad Hoc Network) is an autonomous collection of mobile hosts that communicate over relatively bandwidth constrained wireless
links. Since the nodes are mobile, network topology may change rapidly and unpredictably over time.
The ad hoc wireless networks are generally decentralized, where all network activity including discovering
the topology and delivering messages must be executed by nodes themselves. The MANET can be set
up anywhere and anytime as they are reducing complexities of infrastructure setup and administration
without having infrastructure (such as a base station
in a cellular technology or an access point in a wireless local area network). There is only one medium
∗
Corresponding Author
1
Proceedings of the 6th WSEAS International Conference on Applied Informatics and Communications, Elounda, Greece, August 18-20, 2006 (pp65-73)
possible in this frame work. In[4], the Differentiated
distributed co-ordination function (DDCF) approach
will establish a layered approach of QoS frame work.
A node in higher layer is given more priority because
it will take more responsibilities in administrating
the network and relaying packets between the
clusters and hence receives heavier traffic loads. The
differentiated channel access mechanism is achieved
by varying the channel contention parameters
(Eg,.IFS,CW). The IEEE 802.11e AEDCF function
incorporates flow based different channel contention
parameters to achieve the performance but suffers
with hidden node problems. Various other QoS
aware MAC protocols are specified in the literature
which basically modifies any one of the channel
contention parameters of the IEEE 802.11 to achieve
the performance
the ad hoc scenario.
1.1
Mobile Multimedia Applications
For smooth running of mobile multimedia application
four QoS parameters: bandwidth, cost, delay bounds,
and security, are appropriately set (or allocated) so
that throughout the application the end-user gets the
data as per the user requirement. These factors are
the important parameters for making adaptation decisions in MANETs. Among these four parameters,
bandwidth is the most important measure and is usually monitored in any type of application. Cost and
security factors are rarely mentioned in literatures
about mobile applications, and it is difficult to measure them too. Delay bound is another important
measure, especially for mobile multimedia applications, since streaming media is very sensitive to latency. Besides bandwidth and latency, error rate is
also a very important measure for mobile multimedia
applications because multimedia compression is very
sensitive to errors. Some of the key requirements of
QoS adaptation for mobile multimedia applications
are: automated data format adaptation without user
intervention, graceful quality degradation, seamless
hand offs across networks during roaming, and high
QoS with low jitter, delay, and guaranteed bandwidth. To fulfill these requirements, a lot of different
approaches can be applied to get the QoS adaptation
for mobile multimedia.
1.2
1.3 Proposed Work
We propose a new QoS aware MAC protocol, called
FCP-FAMA, which takes into consideration the requests of the nodes (or mobile users) for the resources
from time to time and schedule the dedicated allocation of the resources to each node. Here, the protocol
is adaptive during the allocation of channel resources
with a democratic approach. The FAMA is used as a
basic channel contention protocol and the FCP over
rides on the FAMA protocol as a centralized authority in allocation of the channel resources.
QoS aware MAC Protocols in MANET and
their limitations
1.4 Organization of the rest of the paper
There are various QoS aware MAC layer protocols
given in the literature as applicable to the adhoc
networks. The MPC-MAC protocol[3] implements
PCF in adhoc networks and gives a QoS approach
by introducing Clustering among the group of nodes
and selecting a mobile point coordinator(MPC) node
which is rich in resources. The MPC as proposed
will create a virtual infrastructure on the fly in the
group of nodes and is maintained dynamically by
periodically broadcasting hello messages. Despite
the benefits of MPC, the protocol does not discuss
an adaptable way of resource allocation among the
group of nodes. More over a single point of failure is
The following sections are organized as follows. Section 2 describes the FCP-FAMA protocol, Section 3
describes the analysis of the protocol and Section 4
gives the simulation results and finally Section 5 concludes the paper.
2 Proposed FCP based FAMA Protocol
The FCP-FAMA protocol runs in a centralized scenario. All the nodes which are in radio range
will select a node which is rich in resources like transmitting power, buffer capacity, and other channel resources. Figure 1 shows the inclusion of FCP-FAMA
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Proceedings of the 6th WSEAS International Conference on Applied Informatics and Communications, Elounda, Greece, August 18-20, 2006 (pp65-73)
any hidden sender that did not hear the RTS being
acknowledged. This is called as ”CTS Dominance”.
When a station with data to send fails to acquire
the floor or detects the floor being held by another
station, it must reschedule its bid for the floor.
This is done using different persistence and backoff
strategies.
2.2 Floor Control Protocol(FCP)
Figure 1: TCP/IP Model with QoS architecture using FCPFAMA
The Floor Control Protocol [2] is the prime protocol
used for the QoS management. Floor control is
a means to manage joint or exclusive access to
shared resources in a (multiparty) network conferencing environment.
The protocol primarily
assigns floor(resources) for the prioritized nodes.
The conference applications often have shared
resources such as right-to-talk, allowing genuine and
justified user get the floor, etc., In many cases, it is
desirable to be able to control who can provide input
(send/write/control, depending on the application)
to the shared resource in the MANETs. Floor
control enables applications or users to gain safe and
mutually exclusive or non-exclusive input access to
the shared object or resource. The floor is an individual temporary access or manipulation permission
for a specific shared resource (or group of resources).
The FCP is primarily responsible for the handling
of the requests from the nodes and scheduling the
resources according to the priority of the requests.
The FCP concept has been extended and few more
features have been added in FCP-FAMA protocol.
in the TCP/IP model. The MAC protocol FAMA is
used as a basic channel contention mechanism. The
FCP governs the allocation of the channel(floor) to
the nodes according to the QoS layed parameters.
Before we discuss the protocol, we describe FAMA
and FCP which are used in the protocol.
2.1
Floor Acquisition Multiple access Protocol(FAMA)
FAMA[1] is a MAC layer protocol which
requires a station who wishes to send one or more
packets to acquire the floor (Channel) before transmitting the packet train. The floor is acquired
using an RTS-CTS exchange multiplexed together
with the data packets in such a way that, although
multiple RTSs and CTSs may collide, data packets
are always sent free of collisions. A station sends
a CTS signal after receiving an error-free RTS addressed to it. When a station receives an error-free
CTS, it knows that the floor has been acquired by a
station to whom the CTS is addressed. After floor
acquisition, either the floor holder or any of the
receivers addressed by the floor holder are able to
send data packets and acknowledgments, without
collisions over the channel. This is accomplished
by forcing stations that do not have the floor to
wait for a predefined minimum amount of time (at
least twice the maximum propagation delay) before
being able to bid for the floor. To ensure that floor
acquisition is enforced among competing senders
hidden from one another and who have requested
the floor (i.e., sent an RTS), the CTS sent by a
receiver is guaranteed to last long enough to jam
2.3 FCP-FAMA Protocol
FCP-FAMA is a QoS and malicious behaviour aware
MAC protocol. The FCP runs at the Cluster head
(CH) of a given MANET, where each of the mobile
hosts runs FAMA at the MAC layer. The Mobile
hosts(or nodes) will start contending for the channel using the FAMA contention, during this channel contention, each node will monitor their throughput, delay parameters and update their available resource parameters. Each node has a traffic based
QoS parameters and these parameters are compared
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Proceedings of the 6th WSEAS International Conference on Applied Informatics and Communications, Elounda, Greece, August 18-20, 2006 (pp65-73)
FCP in the CH in their respective resource request
frames. The resources here is primarily the channel
duration and bandwidth. Normal FAMA based contention is used for the delivery of the request frames.
2. Upon collecting the request frames during a certain period of time, the FCP schedules the forthcomming channel duration for the dedicated allocation to
the nodes. The scheduling process takes in consideration the genuineness and the urgency of the request.
Malicious behavior is detected and energy levels also
is considered. Now the task of the FCP is to convey
this scheduling information to all the nodes in a ’time
scheduling’ frame.
3. This ’time scheduling frame’ is broadcasted to the
nodes by the CH, by using the FAMA channel contention mechanism as like any other node.
4. The nodes upon receiving the ’time scheduling
frame’ will now wait for their turn of transmission
and transmits/receive the data packets for the duration of the time alloted. During a node’s transmission, other nodes will defer their channel access. The
CH will cumulatively acknowledge for all the data
packets received to save the channel contention overheads. The nodes will thus achieve their QoS requirements. The nodes will get a dedicated access to
the resources propositional to the deficiency in their
service as well as the priority of the traffic it holds.
Thus the FCP-FAMA protocol is more adaptive in
the resource allocation process. The democracy is
achieved because each node is getting the share of
resources depending upon their request.
5. After this dedicated channel allocation is over,
all nodes as usual, will content for the channel using
FAMA and this process repeats over a frame duration
of time. Here we have proposed that the nodes upon
receiving the time scheduling frame and waiting for
their chance of transmission will also remember the
stage at which they were during the FAMA channel
contention process and this will be usefull when the
nodes resumes with normal channel contention after
the dedicated channel allocation process is over. The
FCP over FAMA thus achieves the service differentiation among the nodes. The FCP at CH is given
in the algorithm.1. The tuple (pi , ri ) gives the priority of the node sending a particular class of data,
and resource requested for the same. Ti indicates the
against the available resources from time to time. If
a deficiency is found in service, the node creates a
frame consisting of information about the deficiency
in the obtained resources. This deficiency information frame is sent to the FCP in the CH using the normal FAMA contention. The CH receives such frames,
from time to time from all the nodes. A node may
or may not have a service deficiency at a particular
amount of time. Thus a set of frames received by the
CH will vary. The FCP at the CH taking various parameters into consideration will frame the requests.
Once final decision has been taken on channel allocation, FCP allocates accordingly in co-ordination with
FAMA. The FCP will take into consideration about
the urgency, genuineness, fairness greediness, malicious nature, while allocating the resources to any
node. The requested resources are scaled accordingly
keeping the nodes requests relations.
2.4
Function of FCP module
The FCP module of the protocol runs at the application layer of the protocol stack and co-ordinates
with the FAMA at the MAC layer. FCP collects the
transmission requirements from the FAMA, and also
the QoS parameters from the applications at the application layer. Besides that the FCP collects the
information on the malicious behaviour of the node
like greediness, misappropriation of the allotted resources, intentionally dropping the packets etc., The
FCP algorithm is given in Algorithm 1. The FCP
facilitates the dedicated access for the resources.
We have also added the energy management
requirements for the FCP decision making. The FCP
takes this information and computes the priority for
a given n applications at an instant of time. The
Algorithm 2. gives the priority algorithm.
2.5
Description of FCP-FAMA Protocol
The FCP runs at the CH and is responsible for the
following.
1. From time to time, the nodes in the cluster will
send the MAC frames comprising of request for the
resources. The nodes calculate the deficiency in their
alloted resources by comparing with the user set QoS
requirements and this difference is intimated to the
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Proceedings of the 6th WSEAS International Conference on Applied Informatics and Communications, Elounda, Greece, August 18-20, 2006 (pp65-73)
Figure 2: Resource request frame
Figure 3: Time Scheduling Frame
Algorithm 1 FCP at Cluster head
Begin
if (received Packet from nodei =Resource Request
frame(pi , ri )) then
Generate Ui //
set Ti = Ui pP
i ri
set Tsum = i pi ri
end if
if (CHnode.cts is received) then
Tsum
set Tscale =
Tmax
(pi ri )
set slot for node i ;Tslot =
Tscale
P
2.6 FCP-FAMA Protocol System Parameters
set Tf rame = Tslot // QoS frame Scheduling
send Tf rame
The following system parameters are used by the
end if
FCP based FAMA protocol.
resource to be alloted to ith request. Ui which is the
greediness and misappropriation parameter is calculated based on the previous history of the allotted
resources. Tsum will give the net resources demanded
from all the nodes. Tscale will determine a scaling factor which depends upon the available resource Tmax .
Thus each nodes request is scaled accordingly. This
ensures a democratic allocation of resources with priority still maintained among the nodes. The time
scheduling frame is send accordingly.
Algorithm 2 Node FCP process
Begin
if (received Packet from CHnode=Tf rame ) then
if (present time t= node time (Tslot )) then
copy the state of the node
Transmit/Recieve packets
else
copy the state of node
Wait for the time slot in the Tf rame
else
Call REMOTE() of FAMA
end if
end if
Resource Request frame
This frame is generated from the nodes. It comprises
of the preamble, CRC check sum, MAC data and
PLCP Header consisting of source MAC address as
given in Figure.2. The MAC data comprises of packet
priority and insufficiency parameter.
Time Scheduling Frame
This frame is generated upon deciding the resource
allocation parameters by the FCP at the Clusterhead. It consists of Preamble and PLCP Header,
CRC check sum. The MAC data comprises of the
time schedules for the nodes for the dedicated channel access mechanism. Figure 3 shows the details.
The N1,N2... are the resource allocation parameters
which consists of duration and bandwidth of the allotted resources.
The Node runs the FCP process
after receiving time ’scheduling frame’ which will defer its contention for the channel and wait for its designated time frame for the channel access.
3 Analysis
In the Analysis we assume that there are a group
of nodes which send the RTS packets to the channel in poisson distribution with an aggregate mean
arrival rate of λ packets per unit time. The average size of data packet is δ. The length of RTS and
CTS packets are α and β respectively. The maxi5
Proceedings of the 6th WSEAS International Conference on Applied Informatics and Communications, Elounda, Greece, August 18-20, 2006 (pp65-73)
Algorithm 3 Priority algorithm at Cluster head
Begin
if (received Packet from nodei =Resource Request
frame(pi , ri )) then
// capturing malicious behaviour
calculate the allotted resources parameter Ra
calculate the consumed resources parameter Rc
Generate resource utilisation parameter of nodei
as Ui ' f (Ra ∼ Rc )
if Ui is positive then
nodei is in greediness
Set greediness parameter ' modulus Ui ; Ui ∈
(0, 1)
else
if Ui is negetive then
nodei is misappropriating the resources
Set miappropriation parameter ' modulus
Ui ; Ui ∈ (0, 1)
else
nodei is non malicious
Ui = 1
end if
end if
end if
and propagation delay back to the sender, and the
data packet followed by a propagation delay. Accordingly, the time for a successful transmission, T,
is
T = α + β + 3τ + δ
where α is the RTS duration, β is the CTS duration
and τ is the maximum packet transmission delay
and δ is the packet size.
Unsuccessful
transmission: Because FAMA
guarantees that data packets sent after a successful
RTS will not collide with any other packet, an
unsuccessful transmission consists of one RTS being
sent to the channel at time t0 , followed by one or
more RTSs transmitted by other stations with in a
period of X Seconds, (t0 ≤ X ≤ τ ) plus one propagation delay. Therefore the average unsuccessful
transmission is given by
Tunsuccessfully = (α + τ + X)
where X is the first moment of the random variable
X. The cumulative distribution of the X is given by
FY (y) = eλ(τ −y) where (y ≤ λ) therefore
P
X = yeλ(τ −y) where (y ≤ λ)
X = τ − (1 − e(−τ λ) )/λ
mum propagation delay from any node to the CH is
τ seconds. We assume that packets can collide with
each other and hence there is packet retransmission
probability greater than zero. Without loss of generality, we ignore the effect of frame errors due to bit
errors introduced by channel noise. Therefore frames
are received in error only when they encounter collisions due to other simultaneous transmissions. A
successful transmission consists of an RTS with one
propagation delay to the intended recipient, a CTS
SUCCESSFUL TRANSMISSION TIME
UNSUCCESSFUL
TRANSMISSION
Probability of success: The transmission gets successfull when a node send an RTS and with in the
vulnerability period τ there is no other RTS from
other node because all nodes have sensed the RTS
transmission. Therefore the success probability is
that there is no RTS arrivals with in τ seconds. The
probability of RTS arrivals in τ seconds is given by
PRT S arrival in τ seconds = Pa = 1 − e−λτ . Now
the transmission become successfull when there are
no such arrival. Hence
DEDICATED CHANNEL DURATION
Ps = P(no
2t
RTS
Idle
Period
DATA
RTS
t
STATION A
DATA
CTS
CTS
CTS
Idle
Period
RTS
t
RTS
DATA
t
TSF
t
t
seconds)
= 1 − Pa = e−λτ
The success full transmission will occur for a period
of T with probability Ps . An unsuccessful transmission occurs for a period of Tunsuccessf ul .
Dedicated time allocation: The CH will gain
control over the channel using FAMA contention and
sends a time schedule frame of length γ seconds. The
STATION B
CHANNEL
2t
2t
t : Max Propagation delay
TSF : Tine scheduling frame
RTS
DATA
arrivals in τ
VELNE
RABILITY
PERIOD Y
Figure 4: FAMA-FCP-Transmission periods
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Proceedings of the 6th WSEAS International Conference on Applied Informatics and Communications, Elounda, Greece, August 18-20, 2006 (pp65-73)
best effort service traffic class nodes will how ever
follow the normal FAMA channel contention mechanism and during the dedicated channel allocation
these nodes will defer their transmissions till the next
frame arrival.
The Figure 6 shows the channel utilization
achieved by the eight nodes. It is clearly seen that
the priority nodes will attain better utilization and
hence throughput depending on the priority, where as
the best effort traffic class nodes will attain an equal
and lower service priority. Thus FCP over FAMA
improves the throughput performance of the nodes.
The Figure 7 shows the effect of the number of nodes
in the cluster. Increase in the number of nodes will
increase the collision and hence it effects on the utilization. The Figure 8 shows the effect of packet arrival rate λ over the channel utilization. Under lower
rates, the channel is under utilized where as under
higher rate the channel utilization drops due to the
collision. Figure 9 shows the average jitter experience by a FCP-FAMA node as well as FAMA node,
it indicates an improved average jitter performance
in the FCP-FAMA case. The Figure.10 gives the
nodes verses the average jitter for the FCP-FAMA
and FAMA.
frame transmission success probability depends on
the Ps again. When a frame is successfully received
then the channel is dedicated to an individual node
for a period of the priority times the data packet size.
Priority: Let pi (i : 1 ≤ i ≤ k) be the set of
priorities (pi ≥ 1) over which the nodes attain the
priority transmission. Hence the channel is dedicated
for the period of pi δ for each node.
Busy time: Hence a average busy time B is given
by sum of successfull transmission period, unsuccessful transmission period and dedicated time.
B = e−τ λ (β + δ + 2τ ) + α + 2τ −
P
e−τ λ (γ + i pi δ)
(1 − e−τ λ )
+
λ
Idle period: The FAMA imposes a fixed waiting
periods of 2τ before each transmission period of
the channel before making the transition to the
PASSIVE or BACKOFF states [1]. Therefore the
average waiting period is I
I=
1
+ 2τ
λ
Useful period: In the busy period B the amount of
the time each node has utilized the channel is given
by U
Table 1: Variables assigned in simulation
S.No
1
2
3
4
5
6
7
8
9
U = δe−τ λ + pi δe−τ λ
for an ith priority node. Thus the channel utilization
for the ith priority node is given by
S=
4
U
(B + I)
Simulation
This section describes the simulation of the above
proposed QoS aware MAC protocol under the node
configuration scenario given in Figure 5. We considered eight nodes in a cluster with a base-node as a
CH. Among the eight nodes A to H, A,B,C,D, nodes
has set of QoS requirements, where as the other nodes
have the best effort service traffic. The CH collects
the requests from the QoS nodes and run the priority
algorithm to set the priority among those nodes. The
Variable
TP rop τ
TP roc
Ttr
α
β
δ
TF AM A
γ
Rate
Value
0.000001sec
0.000002sec
0.0001 sec
80 bytes duration
240 bytes duration
1024 bytes
2 × Tprop + Ttr + Tproc
480 bytes duration
1MBps
5 Conclusions
We have shown an adaptive MAC protocol which has
a democratic approach for the service differentiation
in different traffic class. We have simulated the protocol ( FCP over FAMA). It showed that the nodes
attains priority while accessing the channel with pri7
Proceedings of the 6th WSEAS International Conference on Applied Informatics and Communications, Elounda, Greece, August 18-20, 2006 (pp65-73)
0.95
No.of FAMA nodes verses Channel utilisation
No.of FCP-FAMA nodes verses channel Utilisation
0.9
Channel utilisation
0.85
0.8
0.75
0.7
0.65
0.6
1
Figure 5: A cluster with 8 priority nodes
2
3
4
5
6
7
8
nodes(sec)
Figure 7: Channel utilization verses active number of nodes
1
Priority 1
priority 2
priority 3
priority 4
no priority
no priority
no priority
no priority
0.9
Channel Utilization
0.45
’f9’ u 1:2
’f9’ u 1:3
’f9’ u 1:4
’f9’ u 1:4
’f9’ u 1:5
’f9’ u 1:6
’f9’ u 1:7
’f9’ u 1:8
’f9’ u 1:9
0.4
0.35
0.7
Throughput
0.3
0.6
0.25
0.2
0.15
0.1
0.5
0.05
0
0.01
0.4
0
1000
2000
3000
4000
5000
6000
7000
8000
0.1
1
Offered load
9000
10
100
time
Figure 6:
FAMA
Figure 8: Throughput of the nodes with offered load
Performance comparision of FCP-FAMA and
ority packet. The nodes loose their priority if they
behave maliciously. The energy level requirements
were taken into consideration. The FCP takes into
consideration the democratic allocation of the channel among the nodes. The improved performance in
jitter and throughput is achieved using the FCP protocol.
40
Average jitter for a FCP-FAMA node
Average jitter for a FAMA node
35
30
average jitter(sec)
Utilisation
0.8
25
20
15
10
References
5
[1] Chane Lee Fullmer . Collision Avoidance Techniques
for Packet Radio Networks PhD Thesis submitted in
Computer Engineering ,University of California Santa
Cruz.June 1998.
0
0
2000
4000
6000
8000
10000
time(sec)
12000
14000
16000
18000
Figure 9: Average jitter experienced by the nodes
8
Proceedings of the 6th WSEAS International Conference on Applied Informatics and Communications, Elounda, Greece, August 18-20, 2006 (pp65-73)
[9] Yunli Chen, Qing-An Zeng and Dharma P. Agrawal,
”Performance evaluation for IEEE 802.11e enhanced
distributed coordination function”, Wireless Communications and Mobile Computing, Vol. 4, pp. 639653,
2004.
7
No.of FCP-FAMA nodes verses average jitter(sec)
No.of FAMA nodes verses average jitter(sec)
6
avg_jitter(sec)
5
4
[10] Tianbo Kuang, Carey Williamson, ”A bidirectional
multi-channel MAC protocol for improving TCP
performance on multihop wireless ad hoc networks”,
Proceedings of the 7th ACM international symposium
on Modeling, analysis and simulation of wireless and
mobile systems, pp. 301 - 310, 2004.
3
2
1
1
2
3
4
nodes(sec)
Figure 10: Average jitter verses active number of nodes
[11] Zygmunt J. Haas, Jing Deng, ”Dual busy tone
multiple access (DBTMA)-a multiple access control
scheme for ad hoc networks”, IEEE Transactions on
Communications, Vol. 50, No. 6, pp. 975 - 985, June
2002.
[2] RFC 4376 / RFC4376 Requirements for Floor Control Protocol. http://www.rfc-editor.org/rfc/rfc4376.txt
[3] Tiantong You and Hossam Hassanein, ”Infrastructurebased MAC in wireless mobile ad-hoc networks”, 27th [12] Phil Karn, ”MACA - A new channel access method
Annual IEEE Conference on Local Computer Netfor packet radio”, ARRL/CRRL Amateur Radio 9th
works, pp. 821 - 830, November 2002.
computer Networking Conference, pp. 134 - 140, 1990.
[4] A. Artikis, L. Kamara, J. Pitt, and M. Sergot. A
[13] Vaduvur Bharghavan, Alan Demers, Scott Shenker,
protocol for resource sharing in norm-governed ad hoc
Lixia Zhang, ”MACAW: a media access protocol for
networks. In Proceedings of the Declarative Agent Lanwireless LAN’s”, Proceedings of the conference on
guages and Technologies (DALT) Workshop. Springer
Communications architectures, protocols and applicaVerlag, 2004.
tions, pp. 210 - 225, 1994.
[5] Luciano Bononi, Luca Budriesi, Danilo Blasi, Vin[14] Kaixin Xu, Mario Ger1a, and Sang Bae, ”How
cenzo Cacace, Luca Casone, Salvatore Rotolo, ”A
effective is the IEEE 802.11 RTS/CTS handshake in
differentiated distributed coordination function MAC
ad hoc networks”, IEEE Global Telecommunications
protocol for cluster-based wireless ad hoc networks”,
Conference, Vol. 1, pp. 72 - 76, 2002.
Proceedings of the 1st ACM international workshop on
performance evaluation of wireless ad hoc, sensor, and
ubiquitous networks, pp. 77 - 86, 2004.
[15] Huei-Jiun Ju, Izhak Rubin, and Yen-Cheng Kuan,
”An adaptive RTS/CTS control mechanism for IEEE
802.11 MAC protocol”, IEEE Vehicular Technology
[6] G Bianchi, IEEE 802.11 Saturation Throughput
Conference, Vol. 2, pp. 1469 - 1473, 2003.
Analysis ,IEEE Communications Letter Vol 2 No 12
Dec 1998.
[16] Chunhung Richard Lin and Mario Gerla, ”Adaptive
clustering for mobile wireless networks”, IEEE Journal
on Selected Areas in Communications, Vol. 15, No. 7,
pp. 1265 - 1275, September 1997.
[7] Sheldon M Ross, Simulation 3 edition Academic Press
2002.
[8] Chunhung Richard Lin and Mario Gerla, ”Adaptive
clustering for mobile wireless networks”, IEEE Journal
on Selected Areas in Communications, Vol. 15, No. 7,
pp. 1265 - 1275, September 1997.
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