Free Essay

Simulation Study on Service Based Adaptive Qos Framework for Vehicular Adhoc Network- Redem

In: Computers and Technology

Submitted By arun009
Words 1550
Pages 7
Vehicular Adhoc Network (VANET) is an outgrowth of Mobile Adhoc Network (MANET), in which the mobile vehicles on road and the stationary roadside units (RSU) constitutes the nodes and communicate with each other on the fly (Fig. 1); Vehicle to Vehicle (V2V) and Vehicle to Roadside Unit (V2R). VANET can be categorised under hybrid architecture that consists of both infrastructure and infrastructure less features. VANET nodes are capable of self organising and managing the information in a distributed fashion with or without any centralised authority. Road Side Units (RSU) supported by DSRC standard [2] acts as gateways or fixed access points to vehicles in mobility and provides interim connectivity to vehicles. One of the major advantages of VANETs over MANETs is the unlimited battery power generated on the fly. VANET plays a major role in defining safety measures by streaming communication between vehicles, infotainment and telematics.
In any generic network phenomena the concept of routing and its characteristics are highly linked with Quality of Service (QoS). The United Nations Consultative Committee for International Telephony and Telegraphy (CCITT) Recommendation E.800 has defined QoS as: “The collective effect of service performance which determines the degree of satisfaction of a user of the service”. The major concern of VANET routing is that whether the performance can satisfy the throughput and delay requirements of such media streaming applications. Unavailability of efficient routing algorithms for the VANET scenario, force the researchers to use the MANET routing algorithms. An analysis of VANET routing protocols shows that its performance is not acceptable due to the feature of very high mobility in terms of speed[3]. Its adverse effect leads to broken links, with high packet drop and overhead due to missing route repairs or failure. This phenomenon leads to low throughput ratio and high delay in transmission.
Figure 1. A VANET Scenario.
This research work proposes an improved version of REDEM, a reliable QoS aware routing scheme for dynamic vehicular ad hoc network ( REDEM), which focuses on identifying optimal paths. The outcome of the research work is compared with the performance of AODV, based on simulation test beds using ns2 simulator. The proposed routing scheme has been designed and implemented as per the DSRC specifications [4] and IEEE 802.11p MAC.
The aim of the research work focuses on:
 Analysis and identify the required optimal QoS for
P.R. Subramaniam et al. / IRRIT, Vol. 1, No. 3, pp. 58-62, September 2011 59 media streaming services over VANET.
 To provide an optimal QoS for highly congested VANET test bed.
 To find a QoS validated route between highly “on mobile” vehicles using REDEM.
The simulated results show that REDEM protocol’s performance is better than the AODV protocol for VANET.
2. QoS issues in VANET
Most of the car manufacturers are involved in implementing wireless connectivity between vehicles and road side units and also between vehicles for the purpose of safety, driving assistance and entertainment. This vehicular network has constraints such as road type, mobility pattern, speed, number of vehicles on road, etc. Providing QoS for media streaming applications in VANET is highly challenging due to highly dynamic vehicle mobility, unpredictable driver’s behaviour which leads to frequent link breakage (short life time of node connection).
A QoS extension for AODV routing packets has been proposed by Perkins [9] to provide QoS. This extension specifies the service requirements which must be met by nodes whilst (re)broadcasting a route request or route reply. In particular it specifies to ensure a delay that does not exceed a maximum value or to ensure a certain amount of network capacity (bandwidth) is made available along a route between communication partners. Another QoS routing protocol based on AODV [10], has used only bandwidth as QoS metric for a route that is identified.
In VANETs, the support for QoS is to be thought as an inherent necessity rather adding such features as an afterthought. Following are the reasons that insist on the need for QoS enabled routing algorithms:
a) Limited bandwidth availability results in rapid fluctuation of wireless channel that severely affects multi-hop flows.
b) Very high speed node mobility may affect the network topology to change frequently that will have an impact on packets contending for the shared media.
c) Interference can affect transmission on adjacent links and nodes beyond neighbours.
3. REDEM modelling and design
REDEM is modelled as a set of high speed vehicles on a straight highway in which any vehicle can establish connectivity with any other vehicle(s) travelling in same direction or opposite direction. Vehicles within communication range can act as intermediate nodes and participate in forwarding the data packets to be transmitted between the source and destination. Periodic “hello” packets floated by the nodes in the network degrades the performance of the VANET by increasing overhead and congestion.
Geographical routing protocols, such as GPSR [5], GPR [6], require geographical node positions to route data between end-points. Receiver based hop selection is proposed for most of the routing protocols [8] at routing layer or at MAC layer [2] [7]. REDEM proposes a distributed, receiver-based next-hop selection routing protocol to minimise the overhead. REDEM metrics are primary to identify the optimal QoS on-demand for various types of services between different nodes in communication. REDEM uses the following metrics:
 Bandwidth
 Delay
 Packet Loss
3.1. REDEM Architectural Design
Fig. 2 shows the architecture of REDEM. The six modules shown in the architecture interact with each other, discover and update the optimal route between the source and destination nodes involved in media streaming. The following are the six modules:
1. Network manager
2. Reverse route identification and neighbour discovery
3. QoS manager
4. Resource manager
5. Optimal route discovery
6. Route update
These six modules make use of two tables – routing table and neighbours table, where the information about the discovered routes and neighbours are stored respectively. The functions performed by these six modules are discussed in 3.2.
Figure 2. A REDEM Architecture.
The labels on the edges connecting the various modules in the architecture are numbers that indicate the sequence of operations carried out by REDEM. Brief description of the operations carried out are by the various modules is given below in the same sequence.
1. Send and receive the RREQ and RREP packets between the source and destination vehicles.
2. Transfer the received packets to the reverse route identification module.
2.1 Update neighbours table with the received frames.
2.2 Create a reverse route entry in the routing table to the source vehicle.
3. Initiate the optimal route discovery.
Network Manager
Route Update
Reverse Route Identification
QoS Manager
Route Discovery
Resource Manager
Routing Table
Neighbors Table
Pkt Loss
Queue model
Signal Strength
P.R. Subramaniam et al. / IRRIT, Vol. 1, No. 3, pp. 58-62, September 2011 60
3.1 Retrieve the existing neighbours’ information from the neighbours table.
4. Transfer of route requests and replies between the resource manager and the QoS manager.
4.1 Allocation of resources by the resource manager along the optimal route to the destination using neighbours table.
5. Forward route requests to route discovery and receive route replies from it.
6. Send the optimal route information to route update.
6.1 Retrieves the routing table information to identify the optimal route.
7. Inform the network manager about the optimal route.
7.1 Update the routing table with the optimal route
3.2. REDEM Modular Design
Module 1: Network Manager
1. This module exchanges the RREQ and RREP packets with the vehicles.
2. Collects the following information from the nodes in the networks:
i. Speed of the vehicle ii. Bandwidth utilised by the vehicle iii. Delay of the service iv. Packet loss of the service
v. Number of vehicles in the network
Module 2: Reverse Route Identification & Neighbour Discovery
When a RREQ control message was received, this module will create a reverse route to the vehicle from which the packet was received.
Algorithm to identify Reverse Route
1. Receive RREQ
2. If RREQ source available in Neighbours table {
If duplicate RREQ {
Discard RREQ
Else {
Add that source to the Neighbours table
Add a reverse route to the source
Information about the vehicle from which the control packet was received, will be added to the Neighbours table. This Neighbours table will provide information during the optimal route discovery process.
Module 3: QoS Manager
1. Negotiate on the QoS parameters required by the source to provide the service or application.
2. Check whether an intermediate vehicle receiving a RREP has sufficient resources to provide that service.
3. Initiates a request to the Resource Manager to identify an optimal route.
QoS Parameters Negotiation
Based on the application requirements by the source, the QoS parameters need to be negotiated with the QoS Manager.
If application == VI {
// VI = Video; AU = Audio; CF = Conference;
// MS = Text Message
Req.Bandwidth(RBW) = 2 Mbps
Req.Delay(RDL) = 50 ms
Req.PacketLoss(RPL) = 5%
Before forwarding a RREQ or RREP to the next neighbour, the vehicle has to check whether it has sufficient resources to be a part of that route.
Receive RREP
If Rep.Bandwidth…...

Similar Documents

Free Essay

Routing Approaches of Delay Tolerant Networks

...Routing Approaches in Delay Tolerant Networks: A Survey R. J. D'Souza National Institute of Technology Karnataka, Surathkal, India Johny Jose National Institute of Technology Karnataka, Surathkal, India ABSTRACT Delay Tolerant Networks (DTNs) have evolved from Mobile Ad Hoc Networks (MANET). It is a network, where contemporaneous connectivity among all nodes doesn’t exist. This leads to the problem of how to route a packet from one node to another, in such a network. This problem becomes more complex, when the node mobility also is considered. The researchers have attempted to address this issue for over a decade. They have found that communication is possible in such a challenged network. The design of routing protocol for such networks is an important issue. This work surveys the literature and classifies the various routing approaches. discontinuity in the network. There are also methods that have employed additional mobile nodes, to provide better message delivery. Researchers are even exploring how the social interaction of humans can be utilized for routing in a DTN. This survey has made an extensive study of the various routing strategies taken by the researchers in the past few years. We have classified them based on the type of knowledge used for routing. 2. FLOODING BASED APPROACHES Knowledge about the network helps in deciding the best next hop. It can happen that the network has absolutely no knowledge about the network. In such a scenario, all nodes......

Words: 6818 - Pages: 28

Premium Essay

Supply Chain Management Based on Modeling & Simulation:

...5 Supply Chain Management Based on Modeling & Simulation: State of the Art and Application Examples in Inventory and Warehouse Management Francesco Longo Modeling & Simulation Center – Laboratory of Enterprise Solutions (MSC-LES) Mechanical Department, University of Calabria Via P. Bucci, Cubo 44C, third floor, 87036 Rende (CS) Italy 1. Introduction The business globalization has transformed the modern companies from independent entities to extended enterprises that strongly cooperate with all supply chain actors. Nowadays supply chains involve multiple actors, multiple flows of items, information and finances. Each supply chain node has its own customers, suppliers and inventory management strategies, demand arrival process and demand forecast methods, items mixture and dedicated internal resources. In this context, each supply chain manager aims to reach the key objective of an efficient supply chain: ‘the right quantity at the right time and in the right place’. To this end, each supply chain node (suppliers, manufacturers, distribution centers, warehouses, stores, etc.) carries out various processes and activities for guarantying goods and services to final customers. The competitiveness of each supply chain actor depends by its capability to activate and manage change processes, in correspondence of optimistic and pessimistic scenarios, to quickly capitalize the chances given by market. Such capability is a critical issue for improving the performance of the......

Words: 17564 - Pages: 71

Premium Essay

A Framework for Assessing Learning Outcomes in Online Business Simulations

...A Framework for Assessing Learning Outcomes in Online Business Simulations Like the last entry, this entry is also derived from a paper I wrote for my master's work in the Technology, Innovation, and Education program at Harvard's Graduate School of Education. My advisor on this project was noted knowledge networks researcher Barry Fishman, visiting Harvard from the University of Michigan. Harvard Business School Publishing is about to launch the first two products in our new series of online business simulations and I wanted to investigate how we can ensure that this product line produces effective learning for our customers. This paper explores a framework for assessing effectiveness in online business simulations. Introduction Problem Statement and Paper Structure Harvard Business School Publishing (HBSP) has created a new product line of online business simulations. We know from faculty customer surveys that they are highly concerned themselves with how easy the simulations are to use, administer, and debrief, and that they are equally concerned that their demanding, and increasingly technically-literate, students rate the learning experience as engaging and dynamic. Hence these eLearning products are designed to be engaging, interactive, usable and teachable. We also know from faculty surveys that these types of learning tools are considered to be very effective. But what does the literature say about these kinds of claims? How can HBS Publishing know...

Words: 425 - Pages: 2

Free Essay

Routing in Wireless Sensor Networks

...Routing in Wireless Sensor Networks: application on Fire Detection Abstract: this paper is about fire detection in building using a modified APTEEN routing protocol. Here we design a system called iFireControl which is a smart detection system for buildings, which is more water efficient than many current systems, while keeping its robustness. introduction A Wireless Sensor network (WSN) consists of spatially distributed autonomous sensors to monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants and to cooperatively pass their data through the network to a main location. The more modern networks are bi-directional, also enabling control of sensors activity. The development of wireless sensor networks was motivated by military applications such as battlefield surveillance; nowadays such networks are used in many industrial and consumer applications, such as industrial process monitoring and control, machine health monitoring, Agriculture, Area Monitoring, Smart Home Monitoring, Seismic Monitoring etc. Wireless Sensor Networks provide a bridge between the real physical and virtual worlds; allow the ability to observe the previously unobservable at a fine resolution over large spatio-temporal scales. The WSN is built of “nodes” from a few to several hundreds or even thousands, where each node is connected to one (or sometimes several) sensors. Each such sensor network node has typically several parts: a...

Words: 4845 - Pages: 20

Premium Essay

Mm of Network Products and Services

...GVCs represent the significant unit of organization of international production, wherein ‘lead firms’, largely multinational corporations (MNCs), coordinate production across international borders through extensive networks of suppliers spread across large numbers of countries. This has resulted in a significant change in the structure of international trade, leading to a domination of what has been referred to as the ‘trade in tasks’, that is, trade is no longer characteristically undertaken in goods, but rather in particular production segments (cut make-trim (CMT) versus the design brand market) of a production chain. The ‘trade in tasks’, empirically measured in terms of trade in intermediate goods, reflect this phenomenon, and the gains accruing to low- and middle-income countries in trade involvement are clearly seen here, with their share constituting more than 35 percent of the world’s intermediate goods trade during the latter half of the 2000s (Milberg 2004). However, it has also been noted extensively that, despite increases in export shares, involvement in GVC-coordinated activities has often not led to any significant increase in value added from those activities over previous commodity-based export regimes because lead firms in global production networks (GPNs) outsource lower value-added activities, while retaining control over production in the higher value-added areas of their ‘core competency’. These areas, often characterized by higher technological and......

Words: 7514 - Pages: 31

Free Essay


...plagiarism test before submission (Turnitin). All reports must have less than 10% of similarity index. Note: Name your report with the given assignment ID before uploading. Penalty of 3 marks for failing to comply. 3. Task You have the option to choose a non research or research based assignment question. However, only 2 groups (Maximum) per question, please register with me ASAP. (First come first served basis) Application Based Assignment a) GPS Tracker and GPS location Spoofing on Mobile You are required to develop a tiny app to demonstrate GPS tracker and GPS location Spoofing technique on mobile computing. Your GPS tracker must able to do GPS satellite scanning and retrieve location information (longitude, latitude, elevation and time). GPS location spoofing is a feature to generate fake location information. The data for location information should be sent and kept in a server. Develop another simple browser-like app to view the data from server. You may use JQuery or any SDK to do this task. Phase 1: GPS tracker & data server storage + literature reviews Phase 2: Location Spoofing & app to retrieve data You are required to do a comprehensive study on the related GPS mobile apps. Three literature studies are needed to compare with your system, including the similarities and differences. Note: No hardware shall be provided. i. Android ii. IOS iii. Window Mobile b) Bluetooth Sensor Tag + server hosting on Mobile You are required to develop a solution to......

Words: 1610 - Pages: 7

Free Essay

Customers’ Attitude Towards Wireless Internet Services in Bangladesh: an Empirical Study Comparing Wimax Based and Edge/Evdo Based Internet Service

...Volume–VI, Number-01, January-June, 2011 Customers’ Attitude towards Wireless Internet Services in Bangladesh: An Empirical Study Comparing WIMAX Based and EDGE/EVDO Based Internet Service S.M. MONIRUL ISLAM* BULBUL AHAMED** Abstract This study is an attempt to measure the attitude of customers towards the wireless Internet services in Bangladesh based on the Mertin Fishbein’s multi attribute attitude model. Some salient attributes (i.e., speed, bandwidth fluctuation rate) of WIMAX based and EDGE/EVDO based Internet services that affect the attitude of the customers have been selected which customers emphasizes to take purchase-decision as well as usage continuation decision. Two types of wireless Internet service providers (WIMAX and EDGE/EVDO) and ten salient attributes have been considered for this study. It has been found from the study that customers form more positive attitude towards WIMAX based Internet service than EDGE/EVDO based service. Observed differences in mean attitude of different attributes for the two categories of wireless Internet services are measured through Z-test to test the significance of those differences. Findings of this study may be used as an index by the Internet service providers for improvement of their services to satisfy the customers. Key words: Wireless Internet, Customer Attitude, WIMAX, EDGE, EVDO 1. INTRODUCTION Communication is the fundamental need of human beings. From the early evolution of civilization man has......

Words: 3584 - Pages: 15

Free Essay

Parameter Optimization for 3g Cellular Networks

...Technische Universität München Lehrstuhl für Kommunikationsnetze Prof. Dr.-Ing. Jörg Eberspächer Master’s Thesis Parameter Optimization for 3G Cellular Networks Author: Matriculation Number: Address: Email Address: Supervisors: Begin: End: TOH, Kok Liang 2706603 Felsennelkenanger 7, App S402 80937 München Deutschland Mr. Roger Abou Jaoude (LKN) Dr.-Ing. Christian Hartmann (LKN) 01. April 2006 01. October 2006 ii Abstract Parameter optimization, such as antenna tilting and CPICH power, can be used to adapt the traffic capacity of 3G systems to traffic demands which are varying in the space and time dimensions. The goal of this thesis is to investigate how parameter optimization can be implemented, both in the 3G cellular system’s initial planning stage to optimize the network for CAPEX saving as well as after the deployment of the network, to increase the capacity of the system. For this purpose, appropriate models, including the space and time domain dynamics of the traffic modeling the moving hotspot characteristics, have been integrated into a system simulation tool. Meta-heuristics techniques such as Tabu Search and Simulated Annealing have been implemented to solve this NP-hard problem. Results show that the existence of optimal configurations can have an achievable capacity gain of more than 30%. iii Acknowledgements This Master Thesis would not have been possible without the support of many people. I would like to......

Words: 23323 - Pages: 94

Premium Essay

Network Services

...within a network. DNS stands for “domain system name” These are the human readable web addresses we use every day. Unfortunately, computers do not understand human language and web addresses must be made readable to computers. This is where DNS comes into play. If you were to type in in the address bar of your browser, would appear. Computers use numerical IP addresses to translate “”. Google’s IP address is and if you were to type this in the address bar the website would populate this way as well. DHCP stands for “Dynamic Host Control Protocol” and is used to automatically assign IP addresses to authorized computers attempting a connection to the network. The way this works is that a computer attempting a connection will send a request to the DHCP server. The server receives and acknowledges the request. The server then sends the acknowledgment back to the user with a leased IP address. When it’s all said and done, the computer attempting to gain access should now be able to access the network. Assigning IP addresses using DHCP is an easy thing to today. Unfortunately the more workstations you have on your computer, the more conscious you need to be about the IP’s assigned. When manually configuring these, it is possible to duplicate IP assignments, configuring the incorrect subnet mask, and incorrectly configuring other TCP/IP parameters. Small networks should have at least one DHCP server, while larger networks......

Words: 303 - Pages: 2

Premium Essay

Network Services

...Windows 2008 Network Services A Network Administrator will need to be able to make recommendations about overhead costs that support the size, security needs and growth possibilities of an organization. One area that will impact the entire organization for years relates to using/installing Domain Name System (DNS) and Dynamic Host Configuration Protocol (DHCP). DNS and DHCP services can be set up in an office by installing the correct equipment or through the ISP that the organization is using. Knowing what is best for the organization should be based on their current size and equipment needs. A small office with only 2 computers would not require new equipment to be installed. In this size office I would recommend statically assigning the IP addresses to the two computers and using the DNS that is on the ISP network. For an office a little bigger, with 5 computers, I would recommend that they install a router/hub in-one device which can also act as a DHCP server. These all-in-one devices are typically less than $200, will add firewall protection and have ports to connect the computers via an Ethernet connection which will allow better internet access. I would still recommend that this office use the DNS on their ISP’s network. For a larger organization with over 25 computers, I would recommend that they install a Server which will have both DNS & DHCP options. With the size of this organization, having the DNS & DHCP on site will allow for quicker response...

Words: 275 - Pages: 2

Free Essay

Study Based on Simplescalar

...PROJECT: STUDY BASED ON SIMPLESCALAR CS202, SPRING 2011 Project Study Based on SimpleScalar Problem 1: Cache Simulation and Associativity Descriptions Configurations: • least-recently-used (LRU) replacement policy • 128 to 2048 sets • 1-way to 4-way associativity • 16-byte cache lines Command Line: ./sim-cheetah -R lru -a 7 -b 11 -n 2 -l 4 2 8 The Simulation under Ubuntu: PAGE 1 / 8 COMPUTER ORGANIZATION AND ARCHITECTURE PROJECT: STUDY BASED ON SIMPLESCALAR CS202, SPRING 2011 Results • simulation statistics sim_num_insn sim_num_refs sim_elapsed_time sim_inst_rate 31394965 # total number of instructions executed 8154766 # total number of loads and stores executed 2 # total simulation time in seconds 15697482.5000 # simulation speed (in insts/sec) Addresses processed: 8155568 Line size: 16 bytes • Miss Ratios Associativity & No. of sets 1 2 3 4 128 256 512 1024 2048 0.18586 0.12974 0.09492 0.05787 0.03718 0.094562 0.062298 0.043441 0.025081 0.014161 0.065089 0.043251 0.030266 0.017734 0.007808 0.051197 0.034149 0.024275 0.012934 0.004801 Analysis Based on the data above, I draw two diagrams for the convenience of comparision. 1 0.2 0.186 2 3 4 0.15 0.13 0.1 0.095 0.095 0.062 0.043 0.034 0.043 0.03 0.024 0.058 0.025 0.018 0.013 0.037 0.014 0.008 0.005 0.05 0 0.065 0.051 128 256 512 1024 2048 PAGE 2 / 8 COMPUTER ORGANIZATION......

Words: 1699 - Pages: 7

Free Essay

Simulation and Research on Data Fusion Algorithm of the Wireless Sensor Network Based on Ns2

...2009 World Congress on Computer Science and Information Engineering Simulation and Research on Data Fusion Algorithm of the Wireless Sensor Network Based on NS2 Junguo Zhang, Wenbin Li, Xueliang Zhao, Xiaodong Bai, Chen Chen Beijing Forestry University, 35 Qinghua East Road, Haidian District,Beijing, 100083 P.R.China information which processed by the embedded system to the user terminals by means of random selforganization wireless communication network through multi-hop relay. Thus it authentically achieves the purpose of ‘monitor anywhere and anytime’. The basic function of sensor network is gathering and sending back the information of the monitoring areas which the relevant sensor nodes are set in. But the sensor network node resources are very limited, which mainly embodies in battery capacity, processing ability, storage capacity, communication bandwidth and so on. Because of the limited monitoring range and reliability of each sensor, we have to make the monitoring areas of the sensor nodes overlapped when they are placed in order to enhance the robustness and accuracy of the information gathered by the entire network. In this case, certain redundancy in the gathered data will be inevitable. On the way of sending monitoring data by multi-hop relay to the sink nodes (or base stations) which are responsible to gather the data. It is necessary to reduce the redundant information by fusion processing. Data fusion is generally defined as......

Words: 3532 - Pages: 15

Free Essay

Study on Vehicular Pollution and Environmental Administration

...Study on Vehicular Pollution and Environmental Administration Course Name: Legal Aspects of Business Faculty: Prof. Name: Roll: 2014PGPMX Submission Date: 15th July 2015 Table of Contents 1. Introduction 3 2. Conceptual Discussion & implementation of the existing system 4 2.1 Vehicular pollutants and their health/environmental effects 4 2.2 Vehicular pollutants and climate changes 4 2.3 Vehicular Pollution Control Measures in India 6 2.4 Vehicular Emission Standards 7 2.5 Emission standards for controlling pollution from new vehicles in India 8 2.6 Road map for Vehicular Emission norms for new vehicles 8 2.7 Inspection & Maintenance (I/M) Practice in India 9 2.8 Pollution Under Control (PUC) Certification system 10 2.9 Noise Standards for Vehicles 12 2.10 Improvement in Fuel Quality 13 2.11 Indian Initiative for Alternate Fuels 13 3. Data Analysis and Interpretation 15 3.1 Environment Protection Act, 1986 15 3.2 The Air (Prevention and Control of Pollution) Act, 1981 16 3.3 The Motor Vehicles Act, 1988 17 3.4 Global Environmental Interaction 19 4. CONCLUSIONS 20 1. Introduction “Nature is the source of all material things: the Maker, the means of making, and the things made. All actions take place in time by the intervening of the forces of Nature; but the man, lost in selfish delusion thinks that he himself is the actor.” (Isha Upanishad) “Environmental conservation is about negotiating the transition from past to......

Words: 6160 - Pages: 25

Premium Essay

Philippine Framework for Assurance Services

...Framework Auditing Standards and Practices Council PHILIPPINE FRAMEWORK FOR ASSURANCE ENGAGEMENTS Framework PHILIPPINE FRAMEWORK FOR ASSURANCE ENGAGEMENTS CONTENTS Paragraph Introduction 1-6 Definition and Objective of an Assurance Engagement 7-11 Scope of the Framework 12-16 Engagement Acceptance 17-19 Elements of an Assurance Engagement 20-60 Inappropriate Use of the Practitioner’s Name 61 Effective Date 62 Acknowledgment 63-64 Appendix: Differences Between Reasonable Assurance Engagements and Limited Assurance Engagements Framework FRAMEWORK PHILIPPINE FRAMEWORK FOR ASSURANCE ENGAGEMENTS Introduction 1. This Framework defines and describes the elements and objectives of an assurance engagement, and identifies engagements to which Philippine Standards on Auditing (PSAs), Philippine Standards on Review Engagements (PSREs) and Philippine Standards on Assurance Engagements (PSAEs) apply. It provides a frame of reference for: (a) Professional accountants in public practice (“practitioners”) when performing assurance engagements. Professional accountants in the public sector refer to the Public Sector Perspective at the end of the Framework. Professional accountants who are neither in public practice nor in the public sector are encouraged to consider the Framework when performing assurance engagements;1 (b) Others involved with assurance engagements, including the intended users of ...

Words: 8077 - Pages: 33

Free Essay

Agent-Based Social Simulation: Dealing with Complexity

...Agent-based social simulation: dealing with complexity Nigel Gilbert Centre for Research on Social Simulation University of Surrey Guildford UK 18 December 2004 While the idea of computer simulation has had enormous influence on most areas of science, and even on the public imagination through its use in computer games such as SimCity, it took until the 1990s for it to have a significant impact in the social sciences. The breakthrough came when it was realised that computer programs offer the possibility of creating ‘artificial’ societies in which individuals and collective actors such as organisations could be directly represented and the effect of their interactions observed. This provided for the first time the possibility of using experimental methods with social phenomena, or at least with their computer representations; of directly studying the emergence of social institutions from individual interaction; and of using computer code as a way of formalising dynamic social theories. In this chapter, these advances in the application of computer simulation to the social sciences will be illustrated with a number of examples of recent work, showing how this new methodology is appropriate for analysing social phenomena that are inherently complex, and how it encourages experimentation and the study of emergence. Social simulation The construction of computer programs that simulate aspects of social behaviour......

Words: 7684 - Pages: 31