A QOS-ORIENTED DISTRIBUTED ROUTING PROTOCOL FOR HYBRID
WIRELESS NETWORKS
By
A
PROJECT REPORT
Submitted to the Department of Computer Science & Engineering in the FACULTY OF ENGINEERING & TECHNOLOGY
In partial fulfillment of the requirements for the award of the degree
Of
MASTER OF TECHNOLOGY
IN
COMPUTER SCIENCE & ENGINEERING
APRIL 2015
BONAFIDE CERTIFICATE
Certified that this project report titled “A QOS-ORIENTED DISTRIBUTED ROUTING PROTOCOL FOR HYBRID WIRELESS NETWORKS” is the bonafide work of Mr. _____________Who carried out the research under my supervision Certified further, that to the best of my knowledge the work reported herein does not form part of any other project report or dissertation on the basis of which a degree or award was conferred on an earlier occasion on this or any other candidate.
Signature of the Guide Signature of the H.O.D
Name Name
CHAPTER 1
ABSTRACT:
As wireless communication gains popularity, significant research has been devoted to supporting real-time transmission with stringent Quality of Service (QoS) requirements for wireless applications. At the same time, a wireless hybrid network that integrates a mobile wireless ad hoc network (MANET) and a wireless infrastructure network has been proven to be a better alternative for the next generation wireless networks. By directly adopting resource reservation-based QoS routing for MANETs, hybrids networks inherit invalid reservation and race condition problems in MANETs. How to guarantee the QoS in hybrid networks remains an open problem.
In this paper, we propose a QoS-Oriented Distributed routing protocol (QOD) to enhance the QoS support capability of hybrid networks. Taking advantage of fewer transmission hops and anycast transmission features of the hybrid networks, QOD transforms the packet routing problem to a resource scheduling problem.
QOD incorporates five algorithms:
1) A QoS-guaranteed neighbor selection algorithm to meet the transmission delay requirement,
2) A distributed packet scheduling algorithm to further reduce transmission delay,
3) A mobility-based segment resizing algorithm that adaptively adjusts segment size according to node mobility in order to reduce transmission time,
4) A traffic redundant elimination algorithm to increase the transmission throughput, and
5) A data redundancy elimination-based transmission algorithm to eliminate the redundant data to further improve the transmission QoS.
Analytical and
simulation results based on the random way-point model and the real human
mobility model show that QOD can provide high QoS performance in terms of
overhead, transmission delay, mobility-resilience, and scalability.
1.2 INTRODUCTION
The rapid development of wireless networks has stimulated numerous wireless applications that have been used in wide areas such as commerce, emergency services, military, education, and entertainment. The number of WiFi capable mobile devices including laptops and handheld devices (e.g., smartphone and tablet PC) has been increasing rapidly. For example, the number of wireless Internet users has tripled world-wide in the last three years, and the number of smartphone users in US has increased from 92.8 million in 2011 to 121.4 million in 2012, and will reach around 207 million by 2017. Nowadays, people wish to watch videos, play games, watch TV, and make longdistanceconferencing via wireless mobile devices “on the go.” Therefore, video streaming applications such as Qik, Flixwagon, and FaceTime on the infrastructure wireless networks have received increasing attention recently. These applications use an infrastructure to directly connect mobile users for video watching or interaction in real time. The widespread use of wireless and mobile devices and the increasing demand for mobile multimedia streaming services are leading to a promising near future where wireless multimedia services (e.g., mobile gaming, online TV, and online conferences) are widely deployed.
The emergence and the envisioned future of real time andmultimedia applications have stimulated the need of high Quality of Service (QoS) support in wireless and mobile networking environments. The QoS support reduces endto- end transmission delay and enhances throughput to guarantee the seamless communication between mobile devices and wireless infrastructures.
At the same time, hybrid wireless networks (i.e., multihop cellular networks) have been proven to be a better network structure for the next generation wireless networks and can help to tackle the stringent end-to-end QoS requirements of different applications. Hybrid networks synergistically combine infrastructure networks and MANETs to leverage each other. Specifically, infrastructure networks improve the scalability of MANETs, while MANETs automatically establish self-organizing networks, extending the coverage of the infrastructure networks. In a vehicle opportunistic access network (an instance of hybrid networks), people in vehicles need to upload or download videos from remote Internet servers through access points (APs) (i.e., base stations) spreading out in a city.
Since it is unlikely that the base stations cover the entire city to maintain sufficiently strong signal everywhere to support an application requiring high link rates, the vehicles themselves can form a MANET to extend the coverage of the base stations, providing continuous network connections. How to guarantee the QoS in hybrid wireless networks with high mobility and fluctuating bandwidth still remains an open question. In the infrastructure wireless networks, QoS provision (e.g., Intserv, RSVP ) has been proposed for QoS routing, which often requires node negotiation, admission control, resource reservation, and, priority scheduling of packets.
However, it is more difficult to guarantee QoS in MANETs due to their unique features including user mobility, channel variance errors, and limited bandwidth. Thus, attempts to directly adapt the QoS solutions for infrastructure networks to MANETs generally do not have great succes. Numerous reservation-based QoS routing protocols have been proposed for MANETs that create routes formed by nodes and links that reserve their resources to fulfill QoS requirements. Although these protocols can increase the QoS of the MANETs to a certain extent, they suffer from invalid reservation and race condition problems. Invalid reservation problem means that the reserved resources become useless if the data transmission path between a source node and a destination node breaks. Race condition problem means a double allocation of the same resource to two different QoS paths. However, little effort has been devoted to support QoS routing in hybrid networks. Most of the current works in hybrid networks focus on increasing network capacity or routing reliability but cannot provide QoS-guaranteed services. Direct adoption of the reservation-based QoS routing protocols of MANETs into hybrid networks inherits the invalid reservation and race condition problems.
In order to enhance the QoS support capability of hybrid networks, in this paper, we propose a QoS-Oriented Distributed routing protocol (QOD). Usually, a hybrid network has widespread base stations. The data transmission in hybrid networks has two features. First, an AP can be a source or a destination to any mobile node. Second, the number of transmission hops between a mobile node and an AP is small. The first feature allows a stream to have anycast transmission along multiple transmission paths to its destination through base stations, and the second feature enables a source node to connect to an AP through an intermediate node. Taking full advantage of the two features, QOD transforms the packet routing problem into a dynamic resource scheduling problem. Specifically, in QOD, if a source node is not within the transmission range of the AP, a source node selects nearby neighbors that can provide QoS services to forward its packets to base stations in a distributed manner. The source node schedules the packet streams to neighbors based on their queuing condition, channel condition, and mobility, aiming toreduce transmission time and increase network capacity. The neighbors then forward packets to base stations, which further forward packets to the destination. In this paper, we focus on the neighbor node selection for QoS-guaranteed transmission. QOD is the first work for QoS routing in hybrid networks.
QOS MULTICAST ROUTING BY USING MULTIPLE PATHS/TREES IN WIRELESSAD HOC NETWORKS
AUTHOR: H. Wu and X. Jia
PUBLISH: Ad Hoc Networks, vol. 5, pp. 600-612, 2009.
In this paper, we investigate the issues of QoS multicast routing in wireless ad hoc networks. Due to limited bandwidth of a wireless node, a QoS multicast call could often be blocked if there does not exist a single multicast tree that has the requested bandwidth, even though there is enough bandwidth in the system to support the call. In this paper, we propose a new multicast routing scheme by using multiple paths or multiple trees to meet the bandwidth requirement of a call. Three multicast routing strategies are studied, SPT (shortest path tree) based multiple-paths (SPTM), least cost tree based multiple-paths (LCTM) and multiple least cost trees (MLCT). The final routing tree(s) can meet the user’s QoS requirements such that the delay from the source to any destination node shall not exceed the required bound and the aggregate bandwidth of the paths or trees shall meet the bandwidth requirement of the call. Extensive simulations have been conducted to evaluate the performance of our three multicast routing strategies. The simulation results show that the new scheme improves the call success ratio and makes a better use of network resources.
QUALITY OF SERVICE PROVISIONING IN AD HOC WIRELESS NETWORKS: A SURVEY OF ISSUES AND SOLUTIONS
AUTHOR: T. Reddy, I. Karthigeyan, B. Manoj, and C. Murthy
PULISH: Ad Hoc Networks, vol. 4, no. 1, pp. 83-124, 2006.
An ad hoc
wireless network (AWN) is a collection of mobile hosts forming a temporary
network on the fly, without using any fixed infrastructure. Characteristics of
AWNs such as lack of central coordination, mobility of hosts, dynamically
varying network topology, and limited availability of resources make QoS
provisioning very challenging in such networks. In this paper, we describe the
issues and challenges in providing QoS for AWNs and review some of the QoS
solutions proposed. We first provide a layer-wise classification of the
existing QoS solutions, and then discuss each of these solutions.
QOS ROUTING BASED ON MULTI-CLASS NODES FOR MOBILE AD HOC NETWORKS
AUTHOR: X. Du, Ad Hoc Networks
PUBLISH: vol. 2, pp. 241-254, 2004.
Efficient routing is very important for Mobile Ad hoc Networks (MANETs). Most existing routing protocols consider homogeneous ad hoc networks, in which all nodes are identical, i.e., they have the same communication capabilities and characteristics. Although a homogeneous network model is simple and easy to analyze, it misses important characteristics of many realistic MANETs such as military battlefield networks. In addition, a homogeneous ad hoc network suffers from poor performance limits and scalability. In many ad hoc networks, multiple types of nodes do co-exist; and some nodes have larger transmission power, higher transmission data rate, better processing capability, and are more robust against bit errors and congestion than other nodes. Hence, a heterogeneous network model is more realistic and provides many advantages (e.g., leading to more efficient routing protocol design). In this paper,
We present a new routing protocol called Multi-Class (MC) routing, which is specifically designed for heterogeneous MANETs. Moreover, we also design a new Medium Access Control (MAC) protocol for heterogeneous MANETs, which is more efficient than IEEE 802.11b. Extensive simulation results demonstrate that the MC routing has very good performance, and outperforms a popular routing protocol — Zone Routing Protocol, in terms of reliability, scalability, route discovery latency, overhead, as well as packet delay and throughput.
PROVISIONING OF ADAPTABILITY TO VARIABLE TOPOLOGIES FOR ROUTING SCHEMES IN MANETS
AUTHOR: S. Jiang, Y. Liu, Y. Jiang, and Q. Yin,
PUBLISH: IEEE J. Selected Areas in Comm., vol. 22, no. 7, pp. 1347-1356, Sept. 2004.
Frequent changes in network topologies caused by mobility in mobile ad hoc networks (MANETs) impose great challenges to designing routing schemes for such networks. Various routing schemes each aiming at particular type of MANET (e.g., flat or clustered MANETs) with different mobility degrees (e.g., low, medium, and high mobility) have been proposed in the literature. However, since a mobile node should not be limited to operate in a particular MANET assumed by a routing scheme, an important issue is how to enable a mobile node to achieve routing performance as high as possible when it roams across different types of MANETs. To handle this issue, a quantity that can predict the link status for a time period in the future with the consideration of mobility is required. In this paper, we discuss such a quantity and investigate how well this quantity can be used by the link caching scheme in the dynamic source routing protocol to provide the adaptability to variable topologies caused by mobility through computer simulation in NS-2.
CHAPTER 2
2.0 SYSTEM ANALYSIS
2.1EXISTING SYSTEM:
Existing approaches for providing
guaranteed services in the infrastructure networks are based on two models: integrated
services (IntServ) and differentiated service (DiffServ) [42]. IntServ is a
stateful model that uses resource reservation for individual flow, and uses
admission control and a scheduler to maintain the QoS of traffic flows. In contrast,
DiffServ is a stateless model which uses coarsegrained class-based mechanism
for traffic management a number of queuing scheduling algorithms. Reservation-based QoS routing protocols have been
proposed for MANETs that create routes formed by nodes and links that reserve
their resources to fulfill QoS requirements although these protocols can
increase the QoS of the MANETs to a certain extent.
2.2 DISADVANTAGES:
PROPOSED SYSTEM:
We propose a QoS-Oriented Distributed routing protocol (QOD). Usually, a hybrid network has widespread base stations.
The data transmission in hybrid networks has two features.
First, an AP can be a source or a destination to any mobile node. Second, the number of transmission hops between a mobile node and an AP is small. The first feature allows a stream to have anycast transmission along multiple transmission paths to its destination through base stations, and the second feature enables a source node to connect to an AP through an intermediate node. Taking full advantage of the two features, QOD transforms the packet routing problem into a dynamic resource scheduling problem. Specifically, in QOD, if a source node is not within the transmission range of the AP, a source node selects nearby neighbors that can provide QoS services to forward its packets to base stations in a distributed manner. The source node schedules the packet streams to neighbors based on their queuing condition, channel condition, and mobility, aiming to reduce transmission time and increase network capacity. The neighbors then forward packets to base stations, which further forward packets to the destination.
ADVANTAGES:
HARDWARE REQUIREMENT:
CHAPTER 3
SYSTEM DESIGN:
Data Flow Diagram / Use Case Diagram / Flow Diagram:
NOTATION:
External sources or destinations, which may be people or organizations or other entities
Here the data referenced by a process is stored and retrieved.
People, procedures or devices that produce data. The physical component is not identified.
Data moves in a specific direction from an origin to a destination. The data flow is a “packet” of data.
MODELING RULES:
There are several common modeling rules when creating DFDs:
3.1 SYSTEM ARCHITECTURE:
3.2 DATAFLOW DIAGRAM
SENSOR NODE:
MOBILE RELAY NODE:
SINK:
UML DIAGRAMS:
3.2 USE CASE DIAGRAM:
3.3 CLASS DIAGRAM:
3.4 SEQUENCE DIAGRAM:
3.5
ACTIVITY DIAGRAM:
3.5 ACTIVITY DIAGRAM:
CHAPTER 4
4.0 IMPLEMENTATION:
QOD ROUTING PROTOCOL:
Scheduling feasibility is the ability of a node to guarantee a packet to arrive at its destination within QoS requirements. As mentioned, when the QoS of the direct transmission between a source node and an AP cannot be guaranteed, the source node sends a request message to its neighbor nodes. After receiving a forward request from a source node, a neighbor node ni with space utility less than a threshold replies the source node. The reply message contains information about available resources for checking packet scheduling feasibility (Section 2.4), packet arrival interval Ta, transmission delay TI!D, and packet deadline Dp of the packets in each flow being forwarded by the neighbor for queuing delay estimation and distributed packet scheduling and the node’s mobility speed for determining packet size. Based on this information, the source node chooses the replied neighbors that can guarantee the delay QoS of packet transmission to APs.
The selected neighbor nodes periodically
report their statuses to the source node, which ensures their scheduling feasibility
and locally schedules the packet stream to them. The individual packets are
forwarded to the neighbor nodes that are scheduling feasible in a round-robin
fashion from a longer delayed node to a shorter delayed node, aiming to reduce
the entire packet transmission delay. Algorithm 1 shows the pseudocode for the
QOD routing protocol executed by each node. The QOD distributed routing
algorithm is developed based on the assumption that the neighboring nodes in
the network have different channel utilities and workloads using IEEE 802.11
protocol. Otherwise, there is no need for packet scheduling in routing, since
all neighbors produce comparative delay for packet forwarding. Therefore, we analyze
the difference in node channel utilities and workloads in a network with IEEE
802.11 protocol in order to see whether the assumption holds true in practice.
4.1 ALGORITHM
The packets travel from different APs, which may lead to different packet transmission delay, resulting in a jitter at the receiver side. The jitter problem can be solved by using token buckets mechanism at the destination APs to shape the traffic flows. This technique is orthogonal to our study in this paper and its details are beyond the scope of this paper.
4.2 MODULES:
HYBRID WIRELESS NETWORKS:
DISTRIBUTED PACKET SCHEDULING:
NEIGHBOR SELECTION ALGORITHM:
MOBILITY-BASED
PACKET RESIZING:
4.3 MODULE DESCRIPTION:
HYBRID WIRELESS NETWORKS:
Hybrid wireless networks (i.e., multihop cellular networks) have been proven to be a better network structure for the next generation wireless networks and can help to tackle the stringent end-to end QoS requirements of different applications. Hybrid networks synergistically combine infrastructure networks and MANETs to leverage each other. Specifically, infrastructure networks improve the scalability of MANETs, while MANETs automatically establish self-organizing networks, extending the coverage of the infrastructure networks.
In a vehicle opportunistic access network (an instance of hybrid networks), people in vehicles need to upload or download videos from remote Internet servers through access points (APs) (i.e., base stations) spreading out in a city. Since it is unlikely that the base stations cover the entire city to maintain sufficiently strong signal everywhere to support an application requiring high link rates, the vehicles themselves can form a MANET to extend the coverage of the base stations, providing continuous network connections.
The QoS requirements mainly include end-to-end delay bound, which is essential for many applications with stringent real-time requirement. While throughput guarantee is also important, it is automatically guaranteed by bounding the transmission delay for a certain amount of packets. The source node conducts admission control to check whether there are enough resources to satisfy the requirements of QoS of the packet stream in the network model of a hybrid network. For example, when a source node n1 wants to upload files to an Internet server through APs, it can choose to send packets to the APs directly by itself or require its neighbor nodes n2, n3, or n4 to assist the packet transmission.
DISTRIBUTED PACKET SCHEDULING:
QoS of the packet transmission and how a source node assigns traffic to the intermediate nodes to ensure their scheduling feasibility in order to further reduce the stream transmission time, a distributed packet scheduling algorithm is proposed for packet routing. This algorithm assigns earlier generated packets to forwarders with higher queuing delays and scheduling feasibility, while assigns more recently generated packets to forwarders with lower queuing delays and scheduling feasibility, so that the transmission delay of an entire packet stream can be reduced.
NEIGHBOR SELECTION ALGORITHM:
Since short delay is the major real-time QoS requirement for traffic transmission, QOD incorporates the Earliest Deadline First scheduling algorithm (EDF), which is a deadline driven scheduling algorithm for data traffic scheduling in intermediate nodes. In this algorithm, an intermediate node assigns the highest priority to the packet with the closest deadline and forwards the packet with the highest priority first. Let us use SpðiÞ to denote the size of the packet steam from node ni, use Wi to denote the bandwidth of node i, and TaðiÞ to denote the packet arrival interval from node ni.
MOBILITY-BASED PACKET RESIZING:
In a highly dynamic mobile wireless network, the transmission link between two nodes is frequently broken down. The delay generated in the packet retransmission degrades the QoS of the transmission of a packet flow. On the other hand, a node in a highly dynamic network has higher probability to meet different mobile nodes and APs, which is beneficial to resource scheduling. As (2) shows, the space utility of an intermediate node that is used for forwarding a packet p is reducing packet size can increase the scheduling feasibility of an intermediate node and reduces packet dropping probability. However, we cannot make the size of the packet too small because it generates more packets to be transmitted, producing higher packet overhead. Based on this rationale and taking advantage of the benefits of node mobility, we propose a mobility-based packet resizing algorithm for QOD in this section. The basic idea is that the larger size packets are assigned to lower mobility intermediate nodes and smaller size packets are assigned to higher mobility intermediate nodes, which increases the QoS-guaranteed packet transmissions. Specifically, in QOD, as the mobility of a node increases, the size of a packet Sp sent from a node to its neighbor nodes i decreases as following:
CHAPTER 5
5.0 SYSTEM STUDY:
5.1 FEASIBILITY STUDY:
The feasibility of the project is analyzed in this phase and business proposal is put forth with a very general plan for the project and some cost estimates. During system analysis the feasibility study of the proposed system is to be carried out. This is to ensure that the proposed system is not a burden to the company. For feasibility analysis, some understanding of the major requirements for the system is essential.
Three key considerations involved in the feasibility analysis are
5.1.1 ECONOMICAL FEASIBILITY:
This study is carried out to check the economic impact that the system will have on the organization. The amount of fund that the company can pour into the research and development of the system is limited. The expenditures must be justified. Thus the developed system as well within the budget and this was achieved because most of the technologies used are freely available. Only the customized products had to be purchased.
5.1.3 SOCIAL FEASIBILITY:
The aspect of study is to check the level of
acceptance of the system by the user. This includes the process of training the
user to use the system efficiently. The user must not feel threatened by the
system, instead must accept it as a necessity. The level of acceptance by the
users solely depends on the methods that are employed to educate the user about
the system and to make him familiar with it. His level of confidence must be
raised so that he is also able to make some constructive criticism, which is
welcomed, as he is the final user of the system.
5.2 SYSTEM TESTING:
Testing is a process of checking whether the developed system is working according to the original objectives and requirements. It is a set of activities that can be planned in advance and conducted systematically. Testing is vital to the success of the system. System testing makes a logical assumption that if all the parts of the system are correct, the global will be successfully achieved. In adequate testing if not testing leads to errors that may not appear even many months. This creates two problems, the time lag between the cause and the appearance of the problem and the effect of the system errors on the files and records within the system. A small system error can conceivably explode into a much larger Problem. Effective testing early in the purpose translates directly into long term cost savings from a reduced number of errors. Another reason for system testing is its utility, as a user-oriented vehicle before implementation. The best programs are worthless if it produces the correct outputs.
5.2.1 UNIT TESTING:
A program represents the logical elements of a system. For a program to run satisfactorily, it must compile and test data correctly and tie in properly with other programs. Achieving an error free program is the responsibility of the programmer. Program testing checks for two types of errors: syntax and logical. Syntax error is a program statement that violates one or more rules of the language in which it is written. An improperly defined field dimension or omitted keywords are common syntax errors. These errors are shown through error message generated by the computer. For Logic errors the programmer must examine the output carefully.
UNIT TESTING:
| Description | Expected result |
| Test for application window properties. | All the properties of the windows are to be properly aligned and displayed. |
| Test for mouse operations. | All the mouse operations like click, drag, etc. must perform the necessary operations without any exceptions. |
5.1.3 FUNCTIONAL TESTING:
Functional testing of an application is used to prove the application delivers correct results, using enough inputs to give an adequate level of confidence that will work correctly for all sets of inputs. The functional testing will need to prove that the application works for each client type and that personalization function work correctly.When a program is tested, the actual output is compared with the expected output. When there is a discrepancy the sequence of instructions must be traced to determine the problem. The process is facilitated by breaking the program into self-contained portions, each of which can be checked at certain key points. The idea is to compare program values against desk-calculated values to isolate the problems.
FUNCTIONAL TESTING:
| Description | Expected result |
| Test for all modules. | All peers should communicate in the group. |
| Test for various peer in a distributed network framework as it display all users available in the group. | The result after execution should give the accurate result. |
5.1. 4 NON-FUNCTIONAL TESTING:
The Non Functional software testing encompasses a rich spectrum of testing strategies, describing the expected results for every test case. It uses symbolic analysis techniques. This testing used to check that an application will work in the operational environment. Non-functional testing includes:
5.1.5 LOAD TESTING:
An important tool for implementing system tests is a Load generator. A Load generator is essential for testing quality requirements such as performance and stress. A load can be a real load, that is, the system can be put under test to real usage by having actual telephone users connected to it. They will generate test input data for system test.
Load Testing
| Description | Expected result |
| It is necessary to ascertain that the application behaves correctly under loads when ‘Server busy’ response is received. | Should designate another active node as a Server. |
5.1.5 PERFORMANCE TESTING:
Performance
tests are utilized in order to determine the widely defined performance of the
software system such as execution time associated with various parts of the code,
response time and device utilization. The intent of this testing is to identify
weak points of the software system and quantify its shortcomings.
PERFORMANCE TESTING:
| Description | Expected result |
| This is required to assure that an application perforce adequately, having the capability to handle many peers, delivering its results in expected time and using an acceptable level of resource and it is an aspect of operational management. | Should handle large input values, and produce accurate result in a expected time. |
5.1.6 RELIABILITY TESTING:
The software reliability is the ability of a system or component to perform its required functions under stated conditions for a specified period of time and it is being ensured in this testing. Reliability can be expressed as the ability of the software to reveal defects under testing conditions, according to the specified requirements. It the portability that a software system will operate without failure under given conditions for a given time interval and it focuses on the behavior of the software element. It forms a part of the software quality control team.
RELIABILITY TESTING:
| Description | Expected result |
| This is to check that the server is rugged and reliable and can handle the failure of any of the components involved in provide the application. | In case of failure of the server an alternate server should take over the job. |
5.1.7 SECURITY TESTING:
Security testing evaluates system characteristics that relate to the availability, integrity and confidentiality of the system data and services. Users/Clients should be encouraged to make sure their security needs are very clearly known at requirements time, so that the security issues can be addressed by the designers and testers.
SECURITY TESTING:
| Description | Expected result |
| Checking that the user identification is authenticated. | In case failure it should not be connected in the framework. |
| Check whether group keys in a tree are shared by all peers. | The peers should know group key in the same group. |
5.1.7 WHITE BOX TESTING:
White box
testing, sometimes called glass-box
testing is a test case
design method that uses
the control structure
of the procedural design to
derive test cases. Using
white box testing
method, the software engineer
can derive test
cases. The White box testing focuses on the inner structure of the
software structure to be tested.
5.1.8 WHITE BOX TESTING:
| Description | Expected result |
| Exercise all logical decisions on their true and false sides. | All the logical decisions must be valid. |
| Execute all loops at their boundaries and within their operational bounds. | All the loops must be finite. |
| Exercise internal data structures to ensure their validity. | All the data structures must be valid. |
5.1.9 BLACK BOX TESTING:
Black box
testing, also called behavioral testing, focuses on the functional requirements
of the software. That is,
black testing enables
the software engineer to derive
sets of input
conditions that will
fully exercise all
functional requirements for a
program. Black box testing is not
alternative to white box techniques.
Rather it is
a complementary approach
that is likely
to uncover a different
class of errors
than white box methods. Black box testing attempts to find
errors which focuses on inputs, outputs, and principle function of a software
module. The starting point of the black box testing is either a specification
or code. The contents of the box are hidden and the stimulated software should
produce the desired results.
5.1.10 BLACK BOX TESTING:
| Description | Expected result |
| To check for incorrect or missing functions. | All the functions must be valid. |
| To check for interface errors. | The entire interface must function normally. |
| To check for errors in a data structures or external data base access. | The database updation and retrieval must be done. |
| To check for initialization and termination errors. | All the functions and data structures must be initialized properly and terminated normally. |
All
the above system testing strategies are carried out in as the development,
documentation and institutionalization of the proposed goals and related
policies is essential.
CHAPTER 7
APPENDIX
7.1 SAMPLE SOURCE CODE
7.2
SAMPLE OUTPUT
CHAPTER 8
CONCLUSION:
We propose a QoS oriented distributed routing protocol (QOD) for hybrid networks to provide QoS services in a highly dynamic scenario. Taking advantage of the unique features of hybrid networks, i.e., anycast transmission and short transmission hops, QOD transforms the packet routing problem to a packet scheduling problem. In QOD, a source node directly transmits packets to an AP if the direct transmission can guarantee the QoS of the traffic. Otherwise, the source node schedules the packets to a number of qualified neighbor nodes.
Specifically, QOD incorporates five algorithms. The QoS-guaranteed neighbor selection algorithm chooses qualified neighbors for packet forwarding. The distributed packet scheduling algorithm schedules the packet transmission to further reduce the packet transmission time. The mobility-based packet resizing algorithm resizes packets and assigns smaller packets to nodes with faster mobility to guarantee the routing QoS in a highly mobile environment.
The traffic redundant elimination-based
transmission algorithm can further increase the transmission throughput. The
soft-deadline-based forwarding scheduling achieves fairness in packet
forwarding scheduling when some packets are not scheduling feasible. Experimental
results show that QOD can achieve high mobility-resilience, scalability, and
contention reduction. In the future, we plan to evaluate the performance of QOD
based on the real testbed.
CHAPTER 9
REFERENCES:
[1] H. Wu and X. Jia, “QoS Multicast Routing by Using Multiple Paths/Trees in Wireless Ad Hoc Networks,” Ad Hoc Networks, vol. 5, pp. 600-612, 2009.
[2] T. Reddy, I. Karthigeyan, B. Manoj, and C. Murthy, “Quality of Service Provisioning in Ad Hoc Wireless Networks: A Survey of Issues and Solutions,” Ad Hoc Networks, vol. 4, no. 1, pp. 83-124, 2006.
[3] X. Du, “QoS Routing Based on Multi-Class Nodes for Mobile Ad Hoc Networks,” Ad Hoc Networks, vol. 2, pp. 241-254, 2004.
[4] S. Jiang, Y. Liu, Y. Jiang, and Q. Yin, “Provisioning of Adaptability to Variable Topologies for Routing Schemes in MANETs,” IEEE J. Selected Areas in Comm., vol. 22, no. 7, pp. 1347-1356, Sept. 2004.
[5] M. Conti, E. Gregori, and G. Maselli, “Reliable and Efficient Forwarding in Ad Hoc Networks,” Ad Hoc Networks, vol. 4, pp. 398-415, 2006.
[6] G. Chakrabarti and S. Kulkarni, “Load Balancing and Resource Reservation in Mobile Ad Hoc Networks,” Ad Hoc Networks, vol. 4, pp. 186-203, 2006.
[7] Z. Shen and J.P. Thomas, “Security and QoS Self-Optimization in Mobile Ad Hoc Networks,” IEEE Trans. Mobile Computing, vol. 7, pp. 1138-1151, Sept. 2008.
[8] S. Ibrahim, K. Sadek, W. Su, and R. Liu, “Cooperative Communications with Relay-Selection: When to Cooperate and Whom to Cooperate With?” IEEE Trans. Wireless Comm., vol. 7, no. 7, pp. 2814-2827, July 2008.