ragavendra (Repaired) - Copy.docx
Transcript of ragavendra (Repaired) - Copy.docx
-
7/28/2019 ragavendra (Repaired) - Copy.docx
1/23
1
A In term Report
On
AN UNUSED BANDWIDTH UTILIZATION IN WIRELESS BROAD
BAND NETWORKS
Submitted
By
M.Ram Rajesh
Roll no: 11203004
M.Tech (C.S.E)
Under The Guidance
Of
Prof. G.Rama Krishna
-
7/28/2019 ragavendra (Repaired) - Copy.docx
2/23
2
ABSTRACT
Applications that intend to transmit large data are bandwidth demanding. In order to
provide Quality of service, each application reserves the bandwidth from base station(BS).
However, it is difficult for the subscriber station (SS) to predict the amount of incoming data.
To provide Qos SS may reserve more bandwidth than its demand. So, reserved bandwidth
may not be fully utilized every time. Indeed a schema proposed termed as Bandwidth
recycling.The idea of the proposed scheme is to send recycled bandwidth to base station and
allow other SSs to utilize the unused bandwidth.
-
7/28/2019 ragavendra (Repaired) - Copy.docx
3/23
3
CONTENTS Page
Abstract 2
1. Introduction 7
2. Analysis 8-19
3. Conclusion 20
4. Design 21-23
5. References 24
-
7/28/2019 ragavendra (Repaired) - Copy.docx
4/23
4
Equation Index
Equation Number Page Number
1 9
2 9
3 10
4 15
5 16
6 16
7 17
8 17
9 17
10 18
-
7/28/2019 ragavendra (Repaired) - Copy.docx
5/23
5
Figure Index
Figure Number Page Number
1 9
2 10
3 10
4 11
5 11
6 12
7 13
8 15
9 18
10 18
-
7/28/2019 ragavendra (Repaired) - Copy.docx
6/23
6
1.INTRODUCTION
1.1.OVERVIEW:
For variable bit rate applications, QoS services are provided by reserving
the bandwidth. So,the subscriber station (SS) is required to reserve the
necessary bandwidth from the base station (BS) in Dynamic Resource
Reservation passion before any data transmissions.
In order to serve variable bit rate (VBR) applications, the SS tends to
keep the reserved bandwidth to maintain the QoS guaranteed services. Thus, the
amount of reserved bandwidth transmitted data may be more than the amount of
transmitted data and may not be fully utilized all the time. Although the amount
of reserved bandwidth is adjustable via making bandwidth requests (BRs), the
adjusted bandwidth is applied as early as to the next coming frame. The unused
bandwidth in the current frame has no chance to be utilized.
Moreover, it is very challenging to adjust the amount of reserved
bandwidth precisely. For every subscriber station a complementary station is
allocated by base station to caliculate unused bandwidth. So unused bandwidth
is added dynamically to base station and base station will allocate bandwidth
dynamically to other subscriber station on the basis of bandwidth requestTo improve the bandwidth utilization while maintaining the same QoS
guaranteed services, research objective is twofold The existing bandwidth
reservation is not changed to maintain the same QoS guaranteed services and
increasing the bandwidth utilization by utilizing the unused bandwidth. A
scheme proposed, named as Bandwidth Recycling , which recycles the unused
-
7/28/2019 ragavendra (Repaired) - Copy.docx
7/23
7
bandwidth while keeping the same QoS guaranteed services without introducing
extra delay.
2.SYSTEM STUDY
2.1 LITERATURE SURVEY:
2.1.1.WiMAX
Physical and medium access layers are used in the WiMAX networks.
The data can be transferred from one node to another by Physical layer.
Medium access layer is used to exchange the information between two systems.
It lives in the data link layer which handles the breakdown of the packets into
bits. WiMAX is used to provide portable mobile broadband connectivity across
cities and countries through a variety of devices.
The original version of the standard on which WiMAX is specified a
physical layer operating in the 10 to 66 GHz range. The WiMAX MAC uses a
scheduling algorithm for which the subscriber station needs to compete onlyonce for initial entry into the network. After network entry is allowed, the
subscriber station is allocated an access slot by the base station. The time slot
can enlarge and contract, but remains assigned to the subscriber station, which
means that other subscribers cannot use it.
In addition to being stable under overload and over-subscription, the
scheduling algorithm can also be more bandwidth efficient. The scheduling
algorithm also allows the base station to control Quality of service (QoS)
parameters by balancing the time-slot assignments among the application needs
of the subscriber station
2.1.2. Base Station
-
7/28/2019 ragavendra (Repaired) - Copy.docx
8/23
8
A base station refers to the wireless access point for computers with
wireless cards. It is basically a router that communicates with devices. A base
station in a network which allocates bandwidth to subscriber stations .
2.1.3. Subscriber Station
The Subscriber Station (SS) is generalized equipment which is used to
provide the connectivity between the base station and the subscriber. Each and
every subscriber station is connected with the base station; the base station
allows the reservation of bandwidth by the subscriber station. Bandwidth
reservation is an important part of the data transmission. Transmission SS (TS)
is one type of SS which has the ability to transfer the data from one SS to
another. The amount of incoming data will vary for the variable bit rate
applications.
2.1.4. Bandwidth Request
Every subscriber station request the bandwidth to base station by sending
BR s. Here bandwidth request strategies are of two types, namely incremental
requests and aggregate requests. When the BS receives an incremental
bandwidth request, it adds the quantity of bandwidth requested to its current
perception of the bandwidth needs of the connection. When the BS receives an
aggregate bandwidth request, it replaces its perception of the bandwidth needs
of the connection with the quantity of bandwidth requested. The self- correctingnature of the request-grant protocol requires that the SSs should periodically use
aggregate Bandwidth requests. The standard states that this period may be a
function of the QoS of a service and of the link quality, but do not give a precise
value for it. The grant-request may be sent in two possible MAC frame types
that are described in the following subsection. Only the first one (the standalone
bandwidth request) can be aggregate or incremental.
-
7/28/2019 ragavendra (Repaired) - Copy.docx
9/23
9
2.1.5. Traffic Classes in IEEE 802.16 Networks
IEEE 802.16 networks have traffic classes,
1. Unsolicited grant services which is used to support real time data with fixed
size.
2. Real time polling service is to support real time data with variable size.
3. Non real time polling service is to support non real time data with fixed size.
4. Best effort service does not have any specific QoS requirements for example
email and web .
2.1.6. Dynamic Reservation Framework
Dynamic reservation is to limit the cost of signalling and configuration
while adapting to varying levels of offered load for a single CB class of traffic.
WIMAX network is a WAN that collects the traffic from primary (WiMAX)
SS, while each primary SS directly connects one or several Access Points on
which actual subscribers are directly connected through secondary SS. In this
type of architecture, if the configuration of a primary SS has to be modified
every time a new CB flow is activated at a secondary SS, the signalling load
between the primary BS and SS would possibly be overly important. Therefore,
it makes sense to limit the configuration load for primary SS by implementing a
semi-static configuration that is seldom modified, but can still support CB
traffic with good QoS, both in the command plane (by limiting the blocking
probability) and in the transfer plane (by ensuring that enough resources are
available for each non-blocked CB flow).
-
7/28/2019 ragavendra (Repaired) - Copy.docx
10/23
10
If the network operator prefers to use only permanent connections, he has
to choose between reserving a large amount of resources (based on the busy
hour offered load of the target traffic) and then risk blocking other types of CB
traffic, or reserving a significantly smaller amount of resources for the target
traffic and then risk a performance degradation for this traffic. The mechanism
allows operating with a minimum amount of reserved resources when the actual
load is small, while seamlessly reserving the necessary amount of resources
when the actual load significantly increases. The cost in term of signalling can
be optimised together with the gain in reserved resources.
2.1.7. Protocol
The unused bandwidth should be initialized to a known state. Unused
bandwidth is calculated to utilize the unused bandwidth. Fig 1 describes the
format of RM. While the TS have the unused bandwidth, it should transmit
Releasing Message to CS. No agreed modulation occurred between TS and CS.
To maximize the probability of receiving of RM by CS, increase the
transmission coverage of the RM. BPSK has the largest coverage among all
modulations supported in the IEEE 802.16 standard. RM is transmitted via
BPSK without maximize the transmitted power of the TS. Fig 3 describes an
example of corresponding locations of TS, BS and CS. The coverage of
modulation is represented in the solid circle. If the unused bandwidth is used by
the TS then Stuff Byte Value (SBV). Broadcast Connection (B-CID) is attached
with the CL and transmitted first, then SBV is transmitted to distinguish the CL
from other broadcast DL transmission intervals. SBV is transmitted to inform
the BS that TS has no more data. To increase the coverage of the RM without
increasing the transmission power of the TS, the RM is transmitted by the TS
via dished circle that is BPSK .
HT=0 EC TYPE REV CI EKS RSV MSB
-
7/28/2019 ragavendra (Repaired) - Copy.docx
11/23
11
Fig.1 Release Message Format
Frame i-1
ULMAP
Separation ComplementaryStation
TS1 TS2 ... TSk B-CID 0xFF CS1 CS2 ... CSk
Fig.2 Bandwidth Recycling
2.1.8. Scheduling Algorithm
Scheduling algorithm is described to schedule a SS with the highest
priority as the CS. The scheduling factor (SF) is defined as the ratio of the
current requested bandwidth (CR) to the current granted bandwidth (CG). Based
on the SF, the priority of each candidate is decided. Higher priority is given to
the SS when bandwidth demand is increased by the SS with higher SF. The SS
with zero CG has the highest priority. Because of the quality of service
LEN
LSB
CID
MSB
CID
LSB
HCS
ULSubframe
TransmissionInterval of
TS k
PossibleTransmissionperiod of CS k
-
7/28/2019 ragavendra (Repaired) - Copy.docx
12/23
12
requirements, the highest priority is given to the non real time polling services,
then Best effort services.
3.PROBLEM DEFINITION AND FEASIBILITY ANALYSIS
3.1.PROBLEM DEFINITON
Important part in bringing out the network services lies in existingtechnology. Routing and switching are the main methods of delivering the data
through the network. Both have their disadvantages and benefits and there are
many variations of them applying in different ways to different situations.
Another big issue is the resource handling with QoS. In IP world, there are a
few proposals to resource handling problems and besides that there are a few
technologies providing different approaches to QoS problems. These include for
instance ATM and Gigabit Ethernet.
3.2.PROJECT OBJECTIVE
Routing and switching are the main methods of delivering the data
through the network.But, the issue is the resource handling with QoS.The
updated reserved bandwidth is applied as early as to the next coming frame and
there is no way to utilize the unused bandwidth in the current frame.
3.3.PROPOSED SYSTEM
Applications that intend to transmit large data are bandwidth demanding.
In order to provide Quality of service, each application reserves the bandwidth
from base station(BS). However, it is difficult for the subscriber station (SS) to
predict the amount of incoming data. To provide Qos SS may reserve more bandwidth than its demand. So, reserved bandwidth may not be fully utilized
-
7/28/2019 ragavendra (Repaired) - Copy.docx
13/23
13
every time. Indeed a schema proposed termed as Bandwidth recycling.The idea
of the proposed scheme is to send recycled bandwidth to base station and allow
other SSs to utilize the unused bandwidth.
4.SYSTEM REQUIREMENTS
4.1.Hardware Requirements:
PROCESSOR : PENTIUM IV 2.6 GHz
RAM : 512 MB DD RAM
MONITOR : 15 COLOR
HARD DISK : 20 GB
FLOPPY DRIVE : 1.44 MB
CDDRIVE : LG 52X
KEYBOARD : STANDARD 102 KEYS
MOUSE : 3 BUTTONS
4.2.Software Requirements:Front End : Java, JFC (Swing)
Backend : MS-Access (Data Base)
Tools Used : Eclipse 3.3
Operating System: Windows XP/7
-
7/28/2019 ragavendra (Repaired) - Copy.docx
14/23
14
5.SYSTEM DESIGN
5.1.MODULE DESCRIPTION:
5.1.1.Bandwidth reservation:
A Dynamic Resource Reservation scheme is introduced to reserve
bandwidth. Every subscriber station in network should reserves the bandwidth
in order to transfer the application by maintaining the quality of service. So,
each subscriber station should send request to base station as Bandwidth
request, base station allocate the bandwidth on priority bases to the subscriber
station.Dynamic reservation is to limit the cost of signalling and configuration
while adapting to varying levels of offered load for a single CB class of traffic.
WIMAX network is a WAN that collects the traffic from primary (WiMAX)
SS, while each primary SS directly connects one or several Access Points on
which actual subscribers are directly connected through secondary SS. In this
type of architecture, if the configuration of a primary SS has to be modifiedevery time a new CB flow is activated at a secondary SS, the signalling load
between the primary BS and SS would possibly be overly important. Therefore,
it makes sense to limit the configuration load for primary SS by implementing a
semi-static configuration that is seldom modified, but can still support CB
traffic with good QoS, both in the command plane (by limiting the blocking
probability) and in the transfer plane (by ensuring that enough resources
are available for each non-blocked CB flow).
-
7/28/2019 ragavendra (Repaired) - Copy.docx
15/23
15
5.1.2.Bandwidth allocation:
For every subscriber station, base station will allocate the bandwidth on
priority based. So priority based scheduling algorithm introduce. Priority based
Scheduling algorithm is described to schedule a SS with the highest priority as
the CS. The scheduling factor (SF) is defined as the ratio of the current
requested bandwidth (CR) to the current granted bandwidth (CG). Based on the
SF, the priority of each candidate is decided. Higher priority is given to the SS
when bandwidth demand is increased by the SS with higher SF. The SS with
zero CG has the highest priority. Because of the quality of service requirements,the highest priority is given to the non real time polling services, then Best
effort services.
5.1.3. Packet creation and data transfer
Split data into n number of fixed size packets with maximum length of
48 characters. By splitting, data can be easily transmitted to great extent without interruption in network across the different nodes.
NODE 1 NODE 4
NODE 2
NODE 3
RREQ
RREP
RREQ
RREP
RREQ
-
7/28/2019 ragavendra (Repaired) - Copy.docx
16/23
16
5.1.4. Bandwidth recycling module
Subscriber Stations scheduled on the uplink (UL) map should havetransmission opportunities in the current frame. Those SSs are called
transmission SSs (TSs). The main idea is to allow the BS to schedule a backup
SS for each TS. The backup SS is assigned to standby for any opportunities to
recycle the unused bandwidth of its corresponding TS. We call the backup SS as
the complementary station (CS).BRs are made in per-connection basis.
However, the BS allocates bandwidth in per-SS basis. It gives the SS flexibilityto allocate the granted bandwidth to each connection locally. Therefore, the
unused bandwidth is defined as the granted bandwidth which is still available
after serving all connections running on the SS. TS has unused bandwidth, it
should transmit a message, called releasing message (RM), to inform its
corresponding CS to recycle the unused bandwidth and transmit to base station .
Frame i-1
ULMAP
Separation ComplementaryStation
TS1 TS2 ... TSk B-CID 0xFF CS1 CS2 ... CSk
Fig 3 Bandwidth recycling
5.1.4. Qos Guaranteed service Module
ULSubframe
TransmissionInterval of
TS k
PossibleTransmissionperiod of CS k
-
7/28/2019 ragavendra (Repaired) - Copy.docx
17/23
17
Reservation of bandwidth is done due to gain the Quality of service
.Quality of service is the ability to provide different priority to different
applications, users, or data flows, or to guarantee a certain level of performance
to a data flow.
6.SYSTEM DESIGN
6.1.CLASS DIAGRAM:
-
7/28/2019 ragavendra (Repaired) - Copy.docx
18/23
18
6.2.SEQUENCE DIAGRAM
-
7/28/2019 ragavendra (Repaired) - Copy.docx
19/23
19
6.3.USE CASE DIAGRAM:
-
7/28/2019 ragavendra (Repaired) - Copy.docx
20/23
20
7.EXPERIMENTAL SNAP SHOTS
Some snap shorts of nodes to send data
NODE 1
-
7/28/2019 ragavendra (Repaired) - Copy.docx
21/23
21
NODE2
-
7/28/2019 ragavendra (Repaired) - Copy.docx
22/23
22
7.CONCLUSION
Variable bit rate applications generate data in variant rates. It is very
challenging for SSs to predict the amount of arriving data precisely. Although
the existing method allows the SS to adjust the reserved bandwidth via
bandwidth requests in each frame, it cannot avoid the risk of failing to satisfy
the QoS requirements. Moreover, the unused bandwidth occurs in the current
frame cannot be utilized by the existing bandwidth adjustment since the
adjusted amount of bandwidth can be applied as early as in the next coming
frame. We proposed bandwidth recycling to recycle the unused bandwidth once
it occurs. It allows the BS to schedule a complementary station for eachtransmission stations. Each complementary station monitors the entire UL
transmission interval of its corresponding TS and standby for any opportunities
to recycle the unused bandwidth .
8.FUTURE SCOPE
One of the factors causing recycling failures is that the CS does not have
data to transmit while receiving a RM. To alleviate this factor, A schema
propose to schedule SSs which have rejected BRs in the last frame because it
can ensure that the SS scheduled as CS has data to recycle the unused
bandwidth. This scheduling algorithm is called Rejected Bandwidth Requests
First Algorithm
-
7/28/2019 ragavendra (Repaired) - Copy.docx
23/23