:45 pm EST

Th 2:00 - 3:15 pm EST

Also by appointment



Course objectives
To provide a general understanding of the basic principles

which govern the design and operation of wireless communication

networks, with emphasis on the wireless link, media access control

and interference issues. We begin by considering the cellular

architecture model, frequency reuse, power control, handoff

and mobility tracking. We then consider wireless local area

networks, including a review of recently proposed standards. 

Next, ad hoc networks will be studied with a focus on

routing/multicasting and \lq\lq capacity" notions. Principles of

of layer integration and energy efficiency will also be

addressed. The special cases of sensor networks and satellite

systems will be reviewed.



Prerequisites
A mastery of Random Processes in Communication and Control

(ENEE 620 or equivalent) and Multiuser Communication (ENEE 625 or

equivalent) is expected. Further, a sound knowledge of Information

Theory (ENEE 721 or equivalent) will make all our cups runneth over.



Course grade
The final grade for the course will be determined by a student's

performance in
a midterm in-class written examination (30%);
a term project (10% for proposal, 20% for final oral presentation
and
40% for final written report). The midterm examination will be held in the last week

of October 2004 (sufficient

advance notice of the exact date will be provided).

The term project will have three components:
a written proposal (due in the last week ofOctober 2004); 
an oral presentation (in the last week of class);
a written project report (due on December 13, 2004).

Details will be provided later.



Please note: There will be no written in-class
final
examination on

December 18, 2004.



Announcement Midterm examination:  Tuesday, Nov. 9, 2004

Planned course topics
1. Introductory concepts Wireless medium (models, properties)
Multiaccess channel
Medium access control
Interference and quality of service.

2. Cellular networks Basic architecture
Frequency reuse
Power control
Mobility control - handoff
Dynamic channel assignment
Registration, paging, mobile IP. 3. Wireless local area networks Comparisons and contrasts with (ordinary) LANs
Bluetooth
IEEE 802.11
Infrared systems. 4. Ad hoc networks (multihop) Notions of "link" and "graph"
Layer interaction
Routing/multicasting
"Capacity" notions.

5. Energy efficiency
Forms of energy consumption
Effects of power control, MAC and routing/multicasting
Limited energy supply.

6. Sensor networks
Objectives and architectures
Energy concerns
Design approaches.

7. Satellite networks Modern satellite systems
Onboard processing capabilities
Satellite constellations
Hybrid networks -- design and performance.



Reading Assignments
1.  R. L. Cruz and A. V. Santhanam, ``Optimal
Routing, Link

     Scheduling and Power
Control in Multi-hop Wireless Networks''



2.  A. E. Gamal, J. Mammen, B. Prabhakar and D. Shah,

     ``Throughput-Delay Trade-off
in Wireless Networks''





GUEST SPEAKERS


Dr. Gerhard Kramer, Bell Labs
             Title: Communication Models and
Information Theory for

                      
Relay Channels with Transmit and Receive Constraints

            
Date: Friday, October 22, 2004

             Time: 11:00 a.m.

            
Location: Room 2460, AVW
Building

            
Abstract: 
                       
A relay network has a source terminal transmitting a

                
message to a destination terminal with the help of one or more relays.

                
Such a situation might occur in a multi-hop or sensor network where

                
there are several terminals that help each other transmit data. 

                
We develop simple communication models for such networks, review

                
existing information theory for the models, and develop several

                 
multi-hopping strategies, where by multi-hopping we mean that the

                 
relays successively decode the message before it arrives at the
destination.

                 
We show that the rates of these strategies are
information-theoretically

                 
optimal for certain wireless scenarios.                   
We extend the results to wider classes of problems, including relays
that

                  
cannot transmit and receive at the same time. For this last case, we
show
                  
that the best coding strategies use random, rather than predetermined,
                  
slot structures.

                  
Relevant Publications:

              
1. Capacity Theorems for Wireless Relay
Channels

              
2. Informationtheoretic Multihopping for
Relay Networks

              
3. Models and Theory for Relay Channels
with Receive Constraints

              
4. Cooperative Strategies and Capacity
Theorems for Relay Networks



     2. 
Dr. Piyush Gupta, Bell Labs



            
Title:  Random-Access
Scheduling with Service Differentiation in
            
                       


                       
Wireless Data Networks            


            
Date: Friday, November 5, 2004

             Time: 11:00 a.m.

            
Location: Room 3120, CSIC

            
Abstract: 

            
      Recent years have seen tremendous
growth in wireless local area

                
networking. An important issue in such networks is that of distributed

                
scheduling. Unlike in cellular networks, there is no central agent

                
that coordinates the medium access of all users in a cell. This leads

                
to significant throughput degradation due to multi-user contention.

                
Existing approaches, such as Slotted Aloha or IEEE 802.11, also fail

                
to provide differentiated service to users. We describe a class of

                
new distributed scheduling algorithms, Regulated Contention Medium

                
Access Control (RCMAC), which provides dynamic prioritized access to

                
users for service differentiation. Furthermore, by regulating

                
multi-user contention, RCMAC achieves higher throughput when traffic

                
is bursty, as is typically the case. We also discuss ongoing work to

                
extend RCMAC to multi-hop wireless networking scenarios, such as

                
ad hoc networks and sensor networks.



                
(Based on joint work with Yogesh Sankarasubramaniam (G.Tech.) and

                 
Alexander Stolyar (Bell Labs).)



                 
Relevant Publications:

              
1. Random-Access Scheduling with Service
Differentiation in

                  
Wireless Networks

              
2. The Capacity of Wireless Networks

              
3. Critical Power for Asymptotic Connectivity in
Wireless Networks

            


      3.  Dr. Vijay Subramanian, Motorola