Air Interface Standards: An Overview
Li Fung Chang, Bellcore
In this tutorial, we will first give a brief descriptions of
impairments of wireless link, possible mitigations schemes and their
impact on wireless data communications. We will then discuss
difference and features of the "high tier" system vs. the "low tier"
system. High tier systems are designed for high mobility vehicular
services. Typical characteristics of a high tier system are large
base station antenna heights, high transmission power, large coverage
area, etc. Low tier systems are targeted for low speed pedestrian and
indoor usage. A low tier system uses small inexpensive base stations
for pole or wall mounting with low transmit power. Wireless
technologies designed to operate in these systems will be quite
different. We will give an overview of several air interface
standards (both U.S. and worldwide) designed for the emerging Personal
Communications Services (PCS). Some are designed for high-tier (e.g.
GSM/DCS1900, IS-95 CDMA, etc.) and some are for low-tier (e.g.
PACS-Personal Access Communication System, PHS-Personal Handyphone
System, DECT-Digital European Cordless Telephone) systems. In
particular, we will focus on the data communication capabilities of
the air interface standards.
Biographical Sketch
Li Fung Chang received the B.S. degree from the National Taiwan Normal
University in 1978 and the M.S., Ph.D. degrees from the University of
Illinois in 1983 and 1985, respectively. She joined Bell
Communications Research in August 1985 as a member of technical staff
in Radio Research Division. She is now a director and project manager
of broadband wireless program. Her research efforts and interests are
mainly in the area of wireless communications. Her early research
works involved in the application of channel coding for wireless
digital radio communications system. She has worked on the ARQ
protocols, architecture for wireless data communications; link level
performance evaluations of TDMA (Time-Division Multiple Access), CDMA
(Code-Division Multiple Access), FHMA (Frequency-Hopping Multiple
Access) wireless communication systems; privacy/authentication for
wireless digital radio communications system; and protocol designs and
system performance evaluations of the PACS for TDD operations for
in-building application. She is also involved in design and network
architecture for the interoperability of the high mobility cellular
system and low mobility PCS system. Currently, she manages a research
group working on protocol design and network performance evaluation of
PCS mobility management on ATM transport and mobile IP over ATM. Dr.
Chang holds three US patents in the aforementioned areas, five pending
patents and has numerous publications. She has given short courses in
PCS at National Chiao-Tung Univ. Taiwan, 1992, and 1995, respectively.
She is a senior member of IEEE, Phi Kappa Phi and Phi Tau Phi Chinese
honor society. Currently, she is chair of the communication chapter,
IEEE NJ Coast Section.