Advanced Computing Report

Done By: Abdullah AL Asbali4487007

Ali AL Mashikhi

4677893Air Traffic Control SystemContents

2Introduction:

2History of ATC:

3Current ATC:

4Pre-Flight Activity on ATC Scenario:

6Pre-Flight Data Flow Diagram:

7Grid Computing

7GridSim:

16Console Diagram Of ATC Pre-Flight

17Conclusion:

17References:

17Appendices:

A list of Figures3Figure 1 Flight activity

6Figure 2 Data Flow Diagram

8Figure 3 Example1

9Figure 4 Example2

10Figure 5 Example3

11Figure 6 Example4

13Figure 7 Example5

Introduction:

ATC or air traffic control is a service provided by grounded based controller. The main job of ground based controller is to direct aircrafts on the ground and in the air. The ground based controller must accomplish two main tasks. The first task is to ensure all aircrafts are safe. The second task is to provide information to pilots. This information is related to the traffic and weather (Nolan, 2009). On this paper we are going to talk about the history of ATC and the ATC nowadays, then we will talk in details about the pre-flight activity. After that, we will explain the five examples that are related to the GridSim. Finally, we will provide a diagram for our ATC system. ATC background:

As it is mentioned in the introduction, ATC is a service. This service is divided into two different parts. The type of the service depends on the place or the location that used by ATC to direct aircrafts. The first type of the service provided by ATC is terminal control. The aim of this service is to control aircrafts and vehicles on the airport ground. A number of facilities are used by the terminal control includes control towers and control center which is called Terminal Radar Approach Centre or TRACON. The second type is responsible for controlling the air traffic in the air or out of the airport (Nolan, 2009). History of ATC:

In the past, there were just a few aircrafts taking off from the airports and landing on the airports ground. The small number of aircrafts made the control of that aircrafts simple. The increase in the aircrafts number has made the control more difficult. For that reason, a number of rules and standards had to be established to ensure the safety of the flights. In 1919, the International Commission for Air Navigation created some rules to control the air traffic. These rules were used by most countries. A number of years later, the rules became not enough because the aircrafts became used in transportation and travelling. 1920, the first form of ATC was established. This old form depends on signals which are sent by flagmen who use flags to communicate with pilots. In 1930, people started to replace flagmen with radar equipped control towers. These years were known as radio communication era. The World War has led to the revolution of the ATC. These advances included radar which used the radio waves to detect objects (Nolan, 2009). Current ATC:

Nowadays ATC provides a wide range of benefits not only for the pilots, the passengers can benefit from the ATC as well. These benefits include:

Provide guidance to pilots.

Provide information about the location and the speed for a specific aircraft.

Coordination of landing and taking off.

Provide information about the weather.

ATC is composed of four elements:

1. Set of flying rules.

2. Navigation system and landing system.

3. The division airport surface and air space.

4. The communication between pilots, controller and equipments (Nalon, 2009).

As mentioned above ATC is responsible for coordinating the aircraft traffic safely on the airport ground and in the air. Every aircraft must follow a number of activities. These activities are:1. Pre-flight

2. Take-off

3. Departure

4. En-route

5. Descent

6. Approach

7. Landing

Figure 1 Flight activityThis paper focuses only on the pre-flight activity and the next section includes full details about the pre-flight activity.

Pre-Flight Activity on ATC Scenario:

The pre-flight activity is This portion of the flight starts on the ground and includes flight checks, push-back from the gate and taxi to the runway (Shafeeq and Saxena).

The pre-flight activity starts when a pilot submits a flight plan form. This form includes information such as, pilot name, aircraft number type, carrier, flight data and time, and final destination. The form will be stored in the Flight Information Database (FID). After that, Air Traffic Management (ATM) Controller requests the plan form the FID. The FID responds to the request by sending the flight details to the ATM Controller. The ATM Controller performs three simultaneous checks. First, it requests weather information from the weather file. The weather file responds to the request by providing the current weather details. Then, the ATM Controller checks on-ground traffic status. The on-ground traffic provides details about the traffic. Finally, the ATM controller checks in the air traffic by sending a request to the air traffic file. The air traffic file includes latest information about the traffic which will be sent to the ATM Controller.

Based on the weather, on-ground traffic, and in the air traffic information, the ATM Controller either to accept or reject the initial flight plan. If the initial flight plan is rejected, the ATM Controller creates an alternative flight plan and sends it to the pilot.

If the initial flight plan is accepted, the pilot receives an acceptance notification from the ATM Controller. After that, the Controller requests a new track number from the Track File. This unique number will be used ATC system to track the aircraft in order to ensure the safety of the whole journey. The Track File, generates the unique track number for the specific flight. Once the track number generated, the controller sends it to the pilot.

The Controller also requests a sending-receiving code from the Communication File. This code is unique and will be used for emergency communications. The Communication File generates the unique code and the Controller sends it to the pilot.

In the case of emergency, the pilot might asks or requests a change on the flight plan from the Terminal Radar Approaching Control (TRACON). The TRACON updates the flight plan on the Flight Database and the Controller will be notified. Then the Controller confirms the pilot about the updated plan (Nalon, 2009) (How stuff works, 2010).

Pre-Flight Data Flow Diagram:

Figure 2 Data Flow DiagramGrid Computing:

A computational grid is a hardware and software infrastructure that provides dependable, consistent, pervasive, and inexpensive access to high-end computational facilities(Ian Foster, 1998). It is one of the hottest computer science research topics. The main concept of the grid is the coordinated resource sharing and problem solving in dynamic multi-domain virtual organizations. The grid computing provides a wide range of benefits for the users. These benefits include the following:

Efficient use of resources.

Provides users with high availability and fault-tolerance.

Enables parallel computing which speeds up the performance.

Used for computing-intensive tasks that require huge computer power such as genetic researches.

since there are no standardized protocols or architectures for the grid computing, the use of grid computing is not yet mature which means it requires a high level of coordination between multi-institutional organizations(VOs). The lack of protocols and standards, and the difficulties of coordination between organizations have made it almost impossible to set up real test environments. Therefore, the GridSim toolkit has been introduced to simulate grid computing environments.

GridSim:

The GridSim toolkit provides a comprehensive facility for simulation of different classes of heterogeneous resources, users, applications, resource brokers, and schedulers(Buyya and Murshed). The GridSim architecture is composed of the following layers:

Users, applications grid scenarios.

Grid Resource Broker.

GridSim Toolkit.

Event simulation architecture.

Virtual Machine.

GridSim provides the following entities and objects among others for simulation (Buyya and Murshed):

User entity: encapsulates a grid user with its processing requirements.

Broker entity: it is the scheduler of users jobs. An instance of a broker is created for each user. Relation between User entity and Broker is almost analogues to that between a user and its CPU in a standalone PC.

Resource entity: GridResource characterised mainly by number of processors, speed, cost and Scheduling policy.

Grid Information Service: contains list of available resources and provides resource registration.

Input and Output entities : establish a means of communication links between different entities.

Processing Elements: represents CPUs treated as single processing unit.

Gridlets: corresponds to a job with its requirements.

Shutdown entity: signals the end of entity.

Report Writer Entity: reports data recorded by GridStatistics.

GridStatistics: records statistical data.

Communication between entities is done via sending and receiving of events. Both entities and events are represented by objects with a body() method that handles the event.

Example1:

Figure 3 Example1Example1 shows the way to create a grid resource. A grid resource is composed of a list of machines. A machine might have one or more processing elements (PE). In this example, a number of steps are required to create the grid resource. These steps include:

1. First step: Initialize the GridSim package

2. Create one Grid resource

1. Creating the machine-list. The aim of creating the machine-list is to store the machines.

2. Creating machines. Every machine has its id, PEs and MIPS.

3. Create a ResourceCharacteristics object. This object stores the properties of a Grid resource

4. Every PE has been assigned a processing speed. This speed is measured in MIPS.

Output of Example1:

A grid resource has been created with 3 machine. Machine 1 has 4 PEs, Machine 2 has 4 PEs, and Machine 3 has 2 PEs.

Example 2:

Figure 4 Example2Example 2 shows how to create a grid user and gridlets. A grid user might have one or more gridlets to be processed. A gridlet corresponds to a process in standalone PC. In this example, five gridlets have been created by using the GridSimRandom class and three gridlets without using it. All the gridlets are stored in a list. After that, every PE has been assigned a rate, the gridlet has been given a length and gridlet file size been determined. In addition, three users have been created and assigned different gridlet.

Example 3:

Figure 5 Example3Example 3 shows how to create a gridlet and send it to other GridSim entities. An object has been created which has three attributes name, speed, and the Gridlet list. To allow the communication, a method must be created to handle that communication. GridSimTags.SCHEDULE_NOW was used to avoid the delay while sending a gridlet to other GridSim entities. The gridlet will be received and stored in a new GridletList object.

Example 4:

Figure 6 Example4The aim of this example is to create a Gridlet and send it to a grid resource entity. As it shown in Example 3, the object first must be created with different attributes. Every entity has been assigned a specific ID. Each grid user has different tasks. The method body handles the communications among GridSim entities. The request will be sent the grid resource to send its characteristics. Once the characteristics are received the event will be recorded in the text file. Another approach has been used to send a gridlet to a grid resource entity. In this example, it shows how to create Gridlets with and without GridSimRandom class.

Output:

After initializing GridSim package, one Grid resource was created with 3 machines. Every machine has some processing elements PEs. All the machines and the properties are stored in the machine list. A Grid user entity was created and assigned a name and an ID. In addition, 8 Gridlets were created. After that, the communications between the Gridlets started. After the completion of the simulation, 8 gridlets were created. Every gridlet has its a resource ID and a specific cost. Example5:Figure 7 Example5The aim of this example is to demonstrate how a Griduser can request GridSim to handle its tasks. It starts by initializing GridSim package, to prepare simulation environment, then creating 3 GridResources each with a list of 3 machines created. These 3 machines have 4, 4 and 2 PEs respectively. Then, the GridResource properties are assigned. After that, a Griduser is created with 8 tasks (Gridlets). The gridlets have to wait for Resources to register themselves with the GIS. After Resources have been registered, the Broker sends a request for a list of available Resources and it inspects their properties and configurations based on user requirements. It then, selects a Resource for its Griduser. Each of the 8 Gridlets is assigned to one of the 3 Resources. Each Resource sends the Gridlet back after execution to the Broker. The Brokers submits the Gridlets to the Griduser. The GIS notifies the entities to issue shutdown events. Then a record for each Gridlet processing details is displayed.

Communication between the above entities(Griduser, Resources, GIS and the Broker) are done via sending and receiving events.

Simulation scenario of ATCs Pre-flight in GridSim:

Using GridSim to simulate the pre-flight scenario of Air Traffic Control (ATC), we may do the following. First, initializing the GridSim. Then, create a GridUser and a GridResource. This GridResource abstracts the whole scenario requirements of the pre-flight activity. We need to create four Processing Elements(PEs) to distribute computation of parallel processes or activities and entitys events on these PEs . These PEs are assembled into a machine. Objects of the machine entity are created as needed and maintained in a machine list. We assume each PE has 400 MIPS. The first PE1 (parent process) corresponds to multiple CPU in a standalone PC, with the difference that these CPUs are controlled centrally as a single unit to the GridResource. This PE1 runs the actions of the pre-flight beginning with the pilot filling and submitting a plan form until he/she gets the flight plan (whatever plan, initial, alternative or emergency) and enters take-off activity . After that, the controller needs to check three things concurrently before responding to the pilot giving him/her a flight plan. These concurrent processes are: 4.Checking Weather, 4.Checking ground traffic and Checking in-air traffic. All start with 4 to demonstrate concurrency. To run simultaneously, the parent process,PE1, creates another 3 PEs (these run java threads), PE2,PE3 and PE4 to execute these 3 checks. Each one have an input and output entities that provide data exchange between it and PE1. Core implementation of each entity or its events is embedded inside its body() method/function. When any PE finishes its execution, its results is sent back to PE1. The PE1 continues the execution until producing the communication code in normal situations or creating the emergency plan in case of emergencies (see the DFD).

Console Diagram Of ATC Pre-Flight

Conclusion:ATC system is a critical service that provides a wide range of benefits to the pilots, airlines and other involved organizations. These benefits include ensuring safety of flights by providing up to date weather forecasts and managing on-air and ground traffic. In this paper, we have gone through ATC history and developments it has undergone. Also, we have mentioned how current ATC works and described its activities. This paper focuses on the pre-flight activity modelled on DFD. It also contains a console diagram (GUI) of a top-level ATC pre-flight simulation scenario in GridSim. References:1. Nalon, M. (2009) Fundamentals of air traffic Control.USA: Delmar

2. Buyya And Murshed, GridSim: A Toolkit for the Modeling and Simulation of Distributed Resource Management and Scheduling for Grid Computing

3. How Stuff works (2010) 1 [online] available from < http://www.howstuffworks.com/> [ 7 Sep 2012].4. Shafeeq, A., and Saxena, V. Design Of Formal Air Traffic Control System Through UMLAppendices:

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Pilot

1.Submit plan form

Aircraft ID

Flight File

Aircraft ID

2.Request Flight Plan Form

ATM Controller

Date or time

Date or time

3.Sends flight plan form

4.Check ground traffic

Flight info

Flight info

4.Check Weather

5.Produce Weather Report

5.Produce ground traffic report

4.Check in air traffic

5.Produce in air traffic reports

Weather File

On-Ground File

In the Air File

Weather inquiry

Weather inquiry

Weather Details

Weather Details

Ground traffic inquiry

Ground traffic inquiry

Ground report

Ground report

Traffic inquiry

Traffic inquiry

Traffic Report

Traffic report

6.Accept the plan

6.Reject the plan

6.Generate alternative plan

Acceptance signal

Rejection signal

New plan

Acceptance signal

Rejection signal

New plan

TRACON

7.Request Track Number

8.Generate Track Number

Track File

Communication File

10.Request sending-receiving code

11.Generate sending-receving code

Flight id

Track num

Comm. Code Inquiry

Comm. Code

Flight id

Track num

Comm Code Inquiry

Comm. Code

9.Send Track Number

12.Send communication Code

Track num

Comm. code

Track num

Comm. code

13.Request a change

Emergency notification

Emergency notification

14.Update plan form

New flight details

New flight details

15.Send Notification

Emergency signal

Emergency signal

16.Generate emergency plan

Emergency plan

Emergency plan