Research Interest of Dr. Khaled M.
lie in the broad area of communication networks
and wireless communications. I am particularly focusing on radio
resource management in 4G wireless networks, traffic engineering for
flow-based routers using operational OSPF networks, and optical
networks. See below for more details.
You can find my publications here.
International Telecommunications Union (ITU) of the United Nations has
defined system requirements for 4G wireless systems in what is known as
IMT-advanced. These requirements are very challenging to satisfy by
today’s current technologies. Our research focuses on a subset of the
core technologies needed for evolving current wireless systems, as
realized in the third generation partnership project (3GPP) Long Term
Evolution (LTE) system and IEEE 802.16e (WiMAX), towards 4th generation
system as defined in the ITU IMT-advanced. We target 4 inter-dependent
research areas essential for achieving spectral eficiency in the
vicinity of 10 bits/sec/Hz.
- Channel-aware Radio Resource
Management and Scheduling: We tackle issues related to power control
and allocation, subchannel allocation, fair allocation, quality of
service scheduling, channel aware and energy aware scheduling.
- Inter-cell Interference
Coordination: Techniques to mitigate interference in OFDMA systems are
key to providing good capacity and enhanced coverage particularly on
cell edges. Viable approaches include adaptive fractional frequency
reuse, power control, opportunistic spectrum access, beamforming, and
coordinated multipoint transmission and reception.
- Self-Organizing Hierarchical
Cellular Systems consisting of macrocells and femtocells: Femtocell are
small base-station devices that can be installed by a user to improve
their local network performance in terms of network coverage, voice
call quality and downlink/uplink data rates. Autonomous operation of
femtocells as expressed by resource management and power level
selection are among several technical challenges in femtocells. We
expect to use game and utility theory to design efficient mechansims
for resource management in femtocells.
- Relaying and Network Coding:
Relaying is a key technology to enhance the downlink capacities in 4G
systems. It is possible by simultaneous transmission of the downlink
from more than one base station. Network coding is a technique that can
be can used to improve the capacity of 4G systems using relays where
relays can send a combination of messages from different sources rather
than simply forwarding the individual messages.
combine the best of two realms:
circuit-switched networks with strong quality of service support as
evidenced by the telephone network, and the cost-effectiveness,
ubiquity, and robustness of (best-effort) packet-switched networks as
evidenced by the Internet. The main mechanism for transforming
best-effort packet-switched networks into a multi-services network is a
framework and architectural mechanisms for supporting quality of
service (QOS). The problem of QOS support is complicated since there
are several potential applications with distinct QOS profiles and
traffic characteristics. Moreover, it is not possible to support any of
these mechanisms without looking on the network at-large and ensuring
that the design of the network at the access, edge, and core levels is
done in a proper manner that supports the highest possible performance
and exhibits good resilience when forced failures or planned attacks
are foreseen. My research in this area concentrates on the following
- Routing and capacity
over-provisioning methods to support robustness against failures in
- Traffic engineering in OSPF
Operational Networks: using the concept of flow-based routers, we seek
methods for traffic engineering and route selection for flows using
default OSPF routing. Our thesis is based on having flow forwarding
table and additonal routing tables for traffic not belonging to a flow.
We can then perform load balancing and route updates on two different
levels to achieve best performance.
the introduction of the lambda and sub-lambda OXCs and the huge
available fiber link capacities, there is an ample supply
of bandwidth to be exploited. On the other hand, most of the current
traffic is switched via SONET/SDH which is pretty inefficient for data
traffic. Therefore, in order to efficiently utilize the huge potential
of optical networks, mechanisms for efficient support of IP traffic
over WDM are crucial. Also, fiber-cuts and node failures could wreak
havoc for operator’s networks. Mechanisms for protection and failure
restoration are of paramount importance in this domain. The main areas
I am focusing on here are:
- Routing, Wavelength, and
Time-Slot Assignment in WDM grooming networks for static and dynamic
traffic. Also, multi-layer network routing where constraints at both
the IP and optical layers are taken into account.
- Protection and restoration
mechanisms in lightpath and light-trails based optical networks.
- Switch architecture design for
all-optical packet switched networks