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ASSESSMENT OF THE
WIMAX STANDARDS WITHIN
E-HEALTH ENVIRONMENT
data should be treated. Each category maintains
a set of service parameters including maximum,
minimum sustained traffic rate, delay and jit-
ter boundaries, priority function. All the traffic
from the upper layer is forwarded to service data
units (SDUs) for servicing MAC connections for
classified packets with similar service demands.
Depending on the number of users and supported
applications, a range of service connections of the
same category may significantly vary during ac-
tive communication providing greater flexibility.
WiMAX also supports scheduling entity which
performs two major functions:
The goal of this section is to investigate the per-
formance of WIMAX networks in the light of
e-Health applications. The methodology that was
proposed at the beginning in this chapter leads to
an investigation of the properties of each chosen
network. Starting with
step 1
of the research
methodology, an overview of the WiMAX stan-
dard and its network management systems with
respect to the various networks within the range
of the WiMAX is presented.
•
Isolation of packets forwarded to different
service classes;
WiMAX Connectivity for
Healthcare Scenarios
•
Allocation of available system resources
between dynamically-added or rejected us-
ers' connections.
IEEE 802.16/WiMAX (Wood, 2007) technology
needs to be used in many examples of e-Health
services where local area connections do not
provide enough coverage Hence, the following is
dedicated to the properties of the WiMAX network.
The standard states that scheduling in BS is
fully responsible for the down link (DL) and the
uplink (UL) resource allocation. However, still
each service station (SS) has its own UL schedul-
ing mechanisms to form transmission policy based
on upper layer QoS requests with full control and
management performed at the base station. To
keep the base station informed of the SSs actual
bandwidth and QoS needs, the standard establishes
a grant-request communication process between
the BS and SSs, respectively. Depending on the
QoS classification each SS has a group of requested
opportunities to apply for available bandwidth
resources to BS. Scheduling in WiMAX has to
accumulate sufficient informative data such as
power level, data rates, QoS requirements, commu-
nications activated, user's number and its priority
to assign time slots and burst profiles to packets
waiting in queues for transmission. Although the
set of functionalities and recommendations speci-
fied for QoS support in WiMAX are conceptually
approved, the scheduling design and explicit
structure is left up to vendors and research bodies
Distinctive Properties of IEEE 802.16
WiMAX is a cost-effective alternative for deliver-
ing highly intensive, rate/delay-sensitive traffic
generally associated with multimedia applications.
With the introduction of IEEE 802.16m data rates
in excess of 75Mbps in Non-Line-of-Sight (NLOS)
conditions are becoming feasible (Andrews,
2007). The QoS concept incorporated in the stan-
dard assumes the ability to manage the incoming
traffic based on application requirements, incor-
porating data with similar demands into service
flows belonging to one out of five service classes
adopted in the standard such as unsolicited grant
services (UGS), real time polling service (rtPS),
extended real-time polling service (ertPS), non
real time polling service (nrtPS) and Best Effort
(BE). These services, together, represent the full set
of categories defining how the application-based
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