Wireless in Local Loop—Some Fundamentals

Abstract

The enhancements in Internet technology and mobile access technology over the last decade, can be leveraged effectively to build Wireless in Local Loop (WiLL) systems, which can enable rapid expansion of telecom and Internet access in developing countries. However, the design of a WiLL system requires one to understand some fundamentals concerning the Access Network and its connectivity to backbone network as well as the traffic requirement for a voice and Internet connection. The requirements of WiLL, in contrast to that of a Mobile cellular system need to be clearly understood. Equally important is the concern for capacity and spectral efficiency, especially as higher bit-rate Internet systems become a must for developing countries to get a fair share of the economic advantages that telecom technologies provide. This paper looks at these fundamental issues in context of GSM, IS-95 and DECT Technologies. This paper further takes a brief look at some recent technological developments, which are likely to impact the Wireless in Local Loop systems.

The paper concludes with a discussion on the emerging third generation (3G) wireless standards, and the new technologies which are being introduced into the network, and what will be their impact on Internet and Multimedia bit-rates and services.

Indexing terms:

• Wireless local loop
• DECT
• GSM
• IS-95
• Fixed wireless access
• Capacity comparisons
• Wireless internet access

Additional information

Notes on contributors

Ashok Jhunjhunwala

Ashok Jhunjhunwala is the Head in Department of Electrical Engineering, Indian Institute of Technology (IIT) Madras, India. Dr Jhunjhunwala leads the team that developed corDECT, India's indigenous Wireless Local Loop technology that's winning accolades the world over. His research interests span Telecommunications, Computer Networks and Fibre Optics, and he's particularly active in developing cost-effective wireless telecommunications solutions.

He is the fellow of the Indian National Academy of Engineering, India. Dr Jhunjhunwala is the first recipient of the Prof S N Mitra Memorial Award (1995). In recognition of his contribution to the Engineering Sciences, he was awarded the S S Bhatnagar Award for the year 1998. Besides coordinating more than 50 projects and presenting over 75 papers at national and international conferences, he edits the Communication section of the Journal of IETE and has authored the book ‘Indian Mathematics’. Earlier, graduating with a B Tech (1975) from IIT Kanpur, he earned an MS (1977) and a PhD (1979) degree from the University of Maine, USA. After a two year stint as Assistant Professor, Electrical Engineering Department, Washington State University, USA, he joined the Department of Electrical Engineering, IIT Madras, India, in 1981 as Assistant Professor. Leading the Telematics and Optical Networks group, Dr Jhunjhunwala has supervised various research teams, directed several engineers and guided many research scholars.

Devendra Jalihal

Devendra Jalihal obtained BTech (Hons) from the Indian Institute of Technology, Kharagpur in 1983, MEng from McMaster University, Hamilton, Canada in 1988 and PhD from Duke University, Durham, USA in 1992, all in Electrical Engineering. From 1983 to 1986, he was with Engineers India Ltd, New Delhi working as Application Engineer. From 1986 to 1992, he was Research Assistant first at McMaster University and later at Duke University. From 1992 to 1994, he was engaged in post doctoral work at Duke University. He has been with the Electrical Engineering Department, IIT Madras since 1994. Presently, he is an Associate Professor. His current research interests include applications of digital signal processing to communication and real-time voice and video communication on packet switched networks. He is also associated with the TeNeT group, IIT Madras and is involved in the development of telecom products for India.

K Giridhar

K Giridhar received the BSc (Applied Sciences) degree from PSG College of Technology, Coimbatore, in 1985, and the ME, degree in Electrical Communication Engineering from Indian Institute of Science, Bangalore, in 1989, and the PhD degree in Electrical and Computer Engineering from University of California, Santa Barbara, CA, in 1993.

He has also worked for a year each, as a Member of Research Staff at Bharat Electronics, Bangalore, and as a Research Affiliate in Electrical Engineering, Stanford University, California. In 1994, he joined the Indian Institute of Technology, Madras, and currently, is an Associate Professor of Electrical Engineering. His present research interests are in the areas of noncoherent and multiuser detection, space-time processing, and 3G wireless. He is involved in telecommunication product development activity based on the DECT Wireless in Local Loop system developed by IITM. Giridhar is also a visiting faculty at Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Andhra Pradesh, and at Stanford University, California.