Wireless & Mobile Systems

Wireless & Mobile Systems

Wireless & Mobile Systems

Goals and Content of this Course :

Part I – Overview & Concepts (4t) (Mardi 16/09/08)

• To give a clear and basic view on the Wireless and Mobile Communications.

1.1 Summary on Communication Networks (Cf.Pujolle 2008, french version)

1.2 History (To be defined : Cf.Papadimitriou – 2005)

1.3 Cf Cours2008_Berlin (Schiller)

Part II – Fundamentals (8t) (Mardi 23/09 - Jeudi 25/09/08)

2 Fundamental aspects on Wireless and Mobile Communications (Cf.See books of Papadimitriou, Molisch, Schiller,…)

Part III – Basic cases on Wireless and Mobile Systems (12t) (Mar 30/09 - Jeudi 02/10 – Mardi 07/10)

3 More details on one case : the GSM (2G) system

4 Basic GSM – GPRS Systems

4.1 GPRS system

Part IV – Wireless networks (8 tiet) – IEEE802.11 (Jeudi 09/10 – Mardi 14/10)

Part V – Pratical Deployments and Implementations (To be prepared by Bui v minh) (8 tiet) (Jeudi 16/10 – Mardi 21/10)

5 Some pratical aspects on Design and Implementation of GSM-GPRS System

5.1 OMC-R case (Software and Hardware Design,Tests and Deployment )

5.2 UMA case (Software and Hardware Design,Tests and Deployment)

Part VI – The Future (4t) (Jeudi 23/10)

6 Advanced systems and Evolution (4G,LTE,SAE, HSPA Evoled,…with OFDM, MIMO)

What Is a Wireless System?

In the most general sense, a wireless system is any collection of elements (or subsystems) that operate interdependently and use unguided electromagnetic-wave propagation to perform some specified function(s) Some examples of systems that fit this definition are :

•Systems that convey information between two or more locations, such as personal communication systems (PCS), police and fire department radio systems, commercial broadcast systems, satellite broadcast systems, telemetry and remote monitoring systems

•Systems that sense the environment and/or objects in the environment, including radar systems that may be used for detecting the presence of objects in some region or volume of the environment and measuring their relative motion and/or position, systems for sensing or measuring atmospheric conditions, and systems for mapping the surface of the Earth or planets

•Systems that aid in navigation or determine the location of an object on the Earth or in space

Each of these systems contains at least one transmitting antenna and at least one receiving

antenna

In contrast to a single-link wired system , the signal environment of a wireless system is hostile :

•The direction of the signal cannot be completely controlled, and the path between endpoints is not unique

•The path between endpoints is time-varying

•Signal dropouts are frequent

•Noise and interference levels are often difficult to predict and time-varying

•Objects in the path between and surrounding the endpoints affect the signal level and its content

•Variations in the signal environment change with geographic location, seasons, and weather

•For mobile systems, as in cellular and PCS systems, at least one of the endpoints may be moving

at an unknown and sometimes significant speed

http://safari.informit.com/9780137146215 - Black

Introduction 2

General Architecture, Basic Concepts, and Terminology

General block diagram of a wireless system for a generic application as shown in Figure 1.1 Many

of the blocks and their functions apply to both wired and wireless communication systems Note, however, that the blocks contained within the dashed outline are fundamental and necessary to wireless systems With the exception of the antennas, all of the remaining blocks may also be found

in wired system applications

Figure 1.1 A Wireless System

Introduction 4

Cấu trúc tổng quát, Khái niệm cơ bản, và Từ ngữ

Sơ đồ tổng quát các khối của hệ thống không giây được biểu hiện trên Hình 1.1 Đa số các khối và chức năngđều đươc dùng cho cả hệ có và không giây Tuy nhiên các khối nằm trong vạch rời là cơ

bản và cần thiết cho hệ thống không giây Trừ các antenna, các khối còn lại đều được dùng cho

các hệ có giây

Hình 1.1 Một hệ thống không giây

Introduction 4

Wireless devices range :

•Mobile :

Cellular (2G,3G,so called ‘4G’), Private Mobile Radio (Analogue, Digital), Mobile mesh,

Emerging technologies including Cognitive Radio and Softre Design Radio

• Fixed :

Point-to-point, Point-to-multipoint, Fixed mesh

• Short – range :

W-LANs (A range of members of the 802.11 family, Zigbee), W-PANs (BlueTooth, High-speed variants such as WiMedia/UWB) RFIDs (Passive devices, Active devices)

•Broadcasting :

Conventional analogue and digital broadcasting Mobile broadcastingto handhelds.

Introduction 5

Figure 1.2 Some Spectrum Allocations in the UHF Band (January 2008)

Introduction 6

What Is a Wireless System?

Conclusion

Ce chapitre a présenté les différents composants d’une architecture réseau, ainsi que le découpage en couches effectué pour prendre en charge les fonctionnalités nécessaires

à la bonne marche de ces systèmes À partir de ces composants, il est possible de

définirdes architectures, et nous avons explicité les trois grandes solutions, OSI, TCP/IP

et UIT-T,prépondérantes dans le domaine des réseaux.

Il faut bien insister, dans le cas de l’architecture OSI, sur le fait qu’elle ne représente

qu’une solution théorique inspirée par le modèle de référence La solution TCP/IP est aujourd’hui la plus répandue, mais il en existe de nombreuses variantes, que nous

examinons

tout au long de cet ouvrage, variantes déterminées essentiellement par les protocoles utilisés en dessous du niveau paquet IP.

L’architecture ATM décrivant le modèle de l’UIT-T est plutôt en décroissance, mais elle

a su trouver sa place en s’intégrant dans l’architecture TCP/IP pour former la technique MPLS.

BS : Base Station

BTS : Base Transceiver System

AP : Access Point

Introduction 7