Media-Independent Handover for Seamless Service Provision in Heterogeneous Networks

Using Packet-level Information in Handover and Admission Control schemes for
Wireless Packet Network
Giuseppe Bianchi, Ilenia Tinnirello
Universita' di Palermo, Dipartimento di Ingegneria Elettrica
Viale Delle Scienze, Parco D'Orleans, 90 128 Palermo, Italy
tel:+39.09 1.6566247fax:+39.091.488452 email: bianchi@elet.polimi.it
Abstract -The algorithm which selects the best candidate
Base Station to connect to i s a key component in Handover and
Admission Control schemes for wireless cellular networks. This
paper shows that, in wireless packet networks based on dynamic
channel slot assignment, this algorithm can exploit additional
packet-level information. The idea i s that connections consume a
different amount of resources even if they have the same
nominal rate. I n fact, corrupted packets can be retransmitted,
and the retransmission overhead reflects the time varying
channel quality perceived by each connection. W e propose two
novel load balancing metrics that effectively account for the
uneven "weight" of each connection in terms of i ts up-to-date
resource consumption. The performance of the proposed
metrics are then evaluated for a particular (i.e. static) scenario.
Although supplementary investigation i s required in dynamic
scenarios, our preliminary results provide new insights in the
field of handover and admission control, and appear to open a
new promising research area.

I . INTRODcTION
u
Handover is the process of transferring a mobile station
(MS) from one base station (BS) to another. An handover
strategy is targeted to optimize the capability of a wireless
cellular network to respond to user mobility while coping
with the needs and requirements affecting the level of Quality
of Service ( QoS) t he network can deliver. The handover

strategy is tightly coupled [ 1,2,3] with the admission control
scheme, i.e. the algorithm which determines whether to reject
or accept a newly originating call.
A separation among the...