Qos Improvement in Cellular Network, Sample of Dissertations

4 pages, 1927 words

QOS IMPROVEMENT IN CELLULAR NETWORKS USING CCSM TECHNIQUE

ABSTRACT

The objective of our project is to improve the Quality of service (QoS) in cellular network using CCSM technique. CCSM is a technique which measures the statistics of a cell periodically. The statistics includes call blocking ratio (CBR), signal to interference plus noise ratio (SINR) and intercell interference (ICI).

These parameters are measured in NME (Network management entity) of the cell cluster and then stored as database. NME is proposed in master base station of a cluster. Usually the center cell of a cluster is taken as master cell. The master base station analyses the statistics of all cells in a cluster periodically. The cells are then ranked based on rule based ranking using AHP (Analytic Hierarchy Process).

The ranking is then communicated to all the cells in a cluster for QoS parameter improvement. Thus by analyzing the cell statistics, QoS parameter such as SINR,CBR,ICI are improved when compared with existing method.

Key words: Qos – CCSM – NME- Master base station- Analytic hierarchy process.

Introduction

Cellular communication is based on a cellular network. Each transmitter in cellular systems for mobile communications, typically called a base station, covers a certain area called a cell. Aservice coverage area of cellular network is divided intomany small areas which are known as hexagonal cells. Eachcell has one base station which is located in its center. Thebase station (BS) is fixed. Several base stations (BSs) areconnected with a mobile switching center (MSC).

3 pages, 1049 words

The Review on Base Station Radio Mobile Waves

Jargon buster 2 G 2 G, the second generation or GSM, is the technology currently used in the operation of mobile phones. 3 G 3 G, or third generation, is the generic term used for the next generation of mobile communications systems. The new systems will enhance the services available today and offer multimedia and internet access and the ability to view video footage. The third generation ...

The MSC is connected to a public switched telephone network (PSTN) and is the control center for the cellular system, coordinating the actions of the base station. A mobile host can communicate only with the base station in its cell directly. When a mobile host wants to set up a call, it sends a request to its base station in its cell on the control channel. The call can be set up only if a channel is assigned to support the communication between the mobile host and the base station. The assignment of channels to cells and to mobile stations is the fundamental operation of a mobile communication system and efficient channel allocation strategies are required to increase call carrying capacity and load balancing. In cellular networks, while the motivation behind all basic channel assignment strategies such as FCA, DCA and HCA is the better utilization of the available frequency spectrum with the consequent reduction of the call blocking probability in each cell and to improve the Quality of service in the network.The maintenance of Quality of Service (QoS) in a wireless environment is a difficult problem.In cellular network, there are no of parameters which are affecting on quality of service of the network. There are various techniques which are used to improve it. One of the parameter is rejection of a call due to unavailability of the free channel. Call can be new call or handoff call.

In order to balance the load among different cells, it isneeded to transfer the over-loaded traffic from hot cells to neighboring cooler ones.That is a cell with traffic load substantially larger than the design load called as hot-spot cell. Different techniques can be used to increase the capacity.Among such techniques, reservation based channel assignment technique is proposed.[1].In cellular networks, blocking occurs when a base station has no free channel to allocate to a mobile user. One distinguishes between two kinds of blocking, the first is called new call blocking which refers to blocking of new calls, and the second is called handoff blocking which refers to blocking of ongoing calls due to the mobility of the users.

4 pages, 1785 words

The Essay on Gell Cell Mobile Phone

Introduction: The new Gel Cell by Alcatel is a mobile phone for specified markets. It is very small, the gel is the actual battery, it comes in many colours, and the most important factor is that it is disposable. It has been developed because of the large demand to produce new products in the over saturated mobile phone market. It is a new product with an unfamiliar concept; therefore the ...

Fig.1. New call and handoff call

By using reservation based channel assignment technique we can assign channel groups to user groups according to call duration so that short duration calls will not be blocked due to long duration calls.

Another approach is hierarchical based scheme dual-band cellular mobile communication network is considered where each cell i.e. the macro and microcells are served by different base stations that are center excited. If the speed of the user is determined to be fast then the call is sent to the macro cell, else if the user were slow then the call would be sent to microcell to be served. When a call is sent to the microcell but the required bandwidth of the call is large than the available bandwidth, then the call would be forwarded to the macro cell[2].

Rana introduces the concept of hybrid channel allocation (HCA) which is the combination of fixed channel allocation (FCA) and dynamic channel allocation (DCA).

When a mobile host needs a channel for its call, and all the channels in its fixed set are busy, only then a request from the dynamic set is made.[3]

Also call blocking can be reduced using auxiliary stations. Failure probability may be minimized if the handoff request is served by an Auxiliary Station (AS) closest to the mobile station (MS), if the channels of base station (BS) are not free. The mobile station, being in the auxiliary station, will send requests to the base station within fixed time intervals and when it will find free channels are available in base station it will automatically connect with it, rejecting the connection of the auxiliary station (AS).

This process effectively reduces the handoff failure probability.[4]

PROPOSED SYSTEM ARCHITECTURE

The proposed system uses a CCSM technique which has network management entity. NME plays an important role in load balancing as it collects the status of all the cells in a cluster.

4 pages, 1552 words

The Essay on Skin Cancer Cells Body Called

Skin Cancer Cancer is a word used to describe a group of diseases. Each has its own name, its own treatment, and its own chances of being cured. Each is different from the others in many ways, but every cancer, whatever its called or whatever part of the body it is located in, is a disease of the body's cells. The millions of tiny cells that make up the human body are so small that they can be ...

This system improves the Quality of Service (QoS) in the cell and avoids unnecessary handoff.

ALGORITHM DESIGN AND DESCRIPTION

Consider a cellular network, in which the cells are alternatively loaded as lightly loaded, medium loaded and heavily loaded.

1) NME, at the centre cell of a cluster sends control signal to all the surrounding BS to know about the status of each cell.

2) Each cell report its measurement to the NME

3) The CCSM in NME detects an overload, if it satisfies the following condition.

* CBR≥CBRth

* SINR≤SINRth

* ICI≥ICIth

Fig 2.Structure of cellular network.

4) Now, CCSM in NME analyses how much the cell is loaded by using the following rules

Rule1: If (load is lightly loaded)

a. Then (status_loadbalance_node is receiver)

Rule2: If (load is heavily loaded)

b. Then (status_loadbalance_node is sender)

Rule3: If (load is medium load)

c. Then (status_loadbalance_node is receiver)

5) After analyzing, it checks the status of the adjacent cells to make a decision using an AHP, and share its load.

6) This process is repeated for an average time of 60sec periodically.

7) When taking decisionusing AHP, we need to do same comparisons.

8) For that, first we need to create a matrix table for the pair wise comparison of alternatives based on each criterion.

9) The matrix table is created by the use of common intensity table.

10) Then the matrixes value must be squared and normalize the value to compute priority vector.

11) Next, criteria comparison also made similar to alternative comparison and compute its priority vector.

12) Now, to develop an overall priority ranking multiply the normalized value of each alternative with its respective criteria value.

13) Then add all the values of criteria for each cell to obtain the output.

14) Depending upon the result of AHP ranking, the load is shared to the desired cell and the process ends.

PARAMETER DISCUSSION

AHP CALCULATION

Analytic hierarchy process is a decision making tool used to solve complex decision problems. A master base station wishes to select a light loaded adjacent cell in a cluster and has 3 aspects in mind which will govern its selection choice: SINR, CBR, ICI. Competing cells for that heavily loaded cell have offered three options. That is they are the adjacent cells of a heavily loaded cells. The NME have looked at these options and decides according to it.

5 pages, 2470 words

The Term Paper on Cell Cycle

?The cell cycle, or cell-division cycle, is the series of events that take place in a cell leading to its division and duplication that produces two daughter cells. In cells without a nucleus, the cell cycle occurs via a process termed binary fission. In cells with a nucleus, the cell cycle can be divided in three periods: interphase—during which the cell grows, accumulating nutrients needed for ...

HIERARCHY TREE

SELECT THE LIGHT LOAD CELL (GOAL)

ICI

CBR

SINR

INTERMEDIATE NEIGHBOURING CELL

The mathematics of the AHP and the calculation techniques are explained here. “The AHP calculations” but its essence is to construct a matrix expressing the relative values of a set of attributes.For example, what is the relative importance to select a light loaded cells? We have to choose whether which cell is much more important, somewhat important, absolutely more important and so on down to very much less important. Each of these judgments is assigned a number on a scale. One common

scale (adapted from Saaty) [5] is the one shown in Table 1.

INTENSITY OF IMPORTANCE | DEFINITION | EXPLANATION |

1 | Equal importance | Two factors contribute equally to the objective |

3 | Somewhat important | Experience and judgment slightly favor one over the other |

5 | Much more important | Experience and judgment strongly favor one over the other |

9 | Absolutely more important | The evidence favoring one over the other is of the highest possible validity |

TABLE 1

A basic, but very reasonable, assumption is that if attribute A is absolutely more important than attribute B and is rated at 9, then B must be absolutely less important than A and is valued at 1/9. These pair wise comparisons are carried out for all factors to be considered and the matrix is completed.

PAIRWISE COMPARISON

EVALUATE ALL ALTERNATIVES WITH RESPECT TO EACH CRITERION

SINR | CELL 1 | CELL 2 | CELL 6 |

CELL 1 | 1 | 1/9 | 1/5 |

CELL 2 | 9 | 1 | 9 |

CELL 6 | 5 | 1/9 | 1 |

NORMALIZED VALUE: 0.044

0.816

0.139

0.999

The same comparison matrix is repeated for CBR&ICI.

3 pages, 1251 words

The Essay on Sickel Cell Anemia

Sickle Cell anemia is a group of inherited red blood cell disorders, or a collection of recessive genetic disorders characterized by a hemoglobin variant called Hb S. Normal red blood cells are round like doughnuts, and they move through small blood tubes in the body to deliver oxygen. Sickle red blood cells become hard, sticky and shaped like sickles used to cut wheat. When these hard and pointed ...

CRITERIA COMPARISON

CRITERIA | SINR | CBR | ICI |

SINR | 1 | 1/9 | 5 |

CBR | 9 | 1 | 3 |

ICI | 1/5 | 1/3 | 1 |

NORMALIZED VALUE: 0.1592

0.7699

0.070

0.9994

To develop an overall priority ranking multiply the normalized value of each alternative with its respective criteria value.Then add all the values of criteria for each cell to obtain the output.

AHP RANKING

CELL 1 | 0.00702 | 0.0338 | 0.0030 | 3

0.04382 |

CELL 2 | 0.13034 | 0.6282 | 0.0573 | 1

0.81584 |

CELL 6 | 0.0223 | 0.10755 | 0.0098 | 2

0.13965 |

RESULTS AND DISCUSSIONS

COMPARISON RESULTS

CHAPTER 4

CODINGS AND RESULTS

STRUCTURE OF CELLULAR NETWORK

PROPOSED MODEL CONSIDERATION OF CELLULAR NETWORK

SNR VS ICI

PERFORMANCE OF SINR VARIATION

THE CELL SELECTED WITH AHP ALGORITHM

Conclusion

The Proposed method is simple to implement and flexible. Using proposed algorithm we can reduce handoff failure when all the channels are busy and can reduce unnecessary hand off. By using this algorithm, call will never get rejected, so call blocking probability is reduced and improves the traffic distribution between cells. It provides satisfactory services to all the users without a call dropping problem and also ensures a reliable Quality of Service to the subscribers.

References

1) Abhijit Sharma, Deepak Kumar “Call Blocking Performance of New Reservation based Channel Assignment Scheme in Cellular” IJCA Special Issue on “2nd National Conference- Computing, Communication and Sensor Network” CCSN, 2011

2) SaravananKandasamy, Prihandoko, BorhanuddinMohd.Ali “New Call Blocking Probability (NCBP) in Improved Adaptive Quality of Service (AdQoS) for Wireless Multimedia Communications using Hierarchical Cellular Approach” 2003.

6 pages, 2853 words

The Term Paper on The Different Types of Cells

There are three major parts of a cell-- the nucleus, cytoplasm, and cell membrane, if these are stained appropriately, they can be easily seen under a light microscope. The nucleus (in many cell types) is the innermost and is enclosed by a thin membrane. The nucleus contains the genetic material which directs the cells function. The cytoplasm includes specialized structures called cytoplasmic ...

3) RanaEjaz Ahmed , “A Channel Allocation Algorithm for Hot-Spot Cells in Wireless Networks” journal of advances in information technology, vol. 1, no. 3, august 2010

4) “Minimization of Call Blocking Probability using Auxiliary Stations” International Journal of Computer Applications (0975 – 8887)Volume 25– No.7, July 2011

5) Using the Analytic hierarchy process for decision making in engineering applications ,EvangelosTriantaphyllou, International journal of industrial engineering, vol- 2

6) An illustrated guide to the Analytic hierarchy process by Dr.Rainer Haas, Dr.OliverMeixner

Introduction

Fig.1. New call and handoff call

Conclusion

References

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