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III. AUTONOMIC RESOURCE ALLOCATION PROCESSES
A. Determine the SuperiorLevel Management
Requirement
The service’s QoS should be ensured according to the
SLA signed by the user when wireless cell is providing
services to mobile users. In SLA, QoE (Quality of
Experience) describes the subjective feelings to the
service properties of the mobile end users, it can be
denoted by a kind of quantization way to indicate the end
users’ experiences and feelings about the service and
network, and reflect the gaps between the current network
and service’s QoS and the expectation of the users [8] .
( )
QE o = f KPI , K, KPI i=
1, K , K (1)
i i1
K represents the number of the QoE parameters used
to measure the satisfaction degree of the users about the
mobile services; n represents the number of the KPI
parameters used to evaluate the ith QoE network
performance parameter .
Wireless access network should also ensure to make
the best use of the network resources to maximize the
benefits of the wireless service providers at the same time
when the quality of the users’ service is ensured, and the
benefits can be denoted by the Network Utility Function,
NUF.
Therefore, the superior level management requirement
of the PBMRAM framework can be represented as:
in
Max ( QoE) & Max ( NUF ) (2)
B. Goal-policy Description
Further, to transform the superior level management
requirement into the policies of each level to serve the
guidance effects. Goal policy describes the administrator’s
expectations and constrains in the performance and
priority of the system. It can be classified to the following
categories according to its effect in the system.
1) System Performance Goal Policy.
System performance goal policy describes the range of
network performance parameters that each type of mobile
service should reach after accessing the wireless cells
according to the SLA users signed .Specific example is
shown in Figure 2.
::=
::= IF < PolicyCondition1 > THEN
::=
::=
Figure 2.Example of System Performance Goal Policy
2) System Performance Optimization Policy.
System performance optimization policy describes that
it should whether or not to degrade the service level and
compress the allocated network resource of the users
according to the service category and the signed SLA
when the resource of wireless access network is not
enough; and whether or not to restore the once degraded
service and increase the allocated resource when the
network load come down and resource is recovered to be
enough. Specific example is shown in Figure 3.
Figure 3. Example of System Performance Optimization Policy
3) Service Handle Priority Policy.
Service handle priority policy describes the priority of
all the service types and users when more than one mobile
users are applying to access to the wireless cell. Specific
example is shown in Figure4.
::= |
::= IF THEN
::=
::=
::= IF THEN
::=
Figure 4.Example of Service Handle Priority Policy
C. System Utility Analysis
Then we will generate the utility policy which
describes the system performance optimization
assessment model, by combining the state determination
knowledge and the network quality parameters
performance model instituted by the experts in the
knowledge base. The utility functions in the utility policy
are the quantization assessments of the user’s QoE and the
system’s NUF.
1) Service Categories Utility Functions.
The users in mobile environment can be classified into
four types: conversational class, stream class, interactive
class and background class, each class is related to several
rock-bottom parameters of network performance. To
simplify the system modeling, here the utility functions of
all the classes are hypothetic to be only related to the
allocated bandwidth resource.
Now, conforming to document[9],we present the
utility functions of each service classes used in utility
policies in PBMRAM, and the maximum utility value of
each class is 1 hypothetically.
a) Conversational Class Service. It is a real-time
service, and its characteristics are like this. Its demand of
data transmitting rate is not high, but it requires the
relative small delay and jitter, and low bit error rate.
Therefore, it is sensitive to the change of bandwidth, the
minimum bandwidth is hypothetically B minl, when the
broadband is b 1 , the utility function U 1 (b 1 ) can be
represented as:
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