22-05-2012, 12:59 PM
Adaptive Medium Access Control for Next Generation Wireless Terminals
[attachment=22698]
INTRODUCTION
NEXT GENERATION (NG) wireless networks are expected
to provide mobile users with a freedom of roaming
between diverse set of wireless architectures as shown in Fig. 1.
Since an NG wireless terminal will operate in these various
types of networks, the Medium Access Control (MAC) layer
will encounter different protocols that are already deployed in
the access points (AP) of these networks.
RELATED WORK
There exist several studies in the literature to address the
integration of existing wireless systems. In [19], a unified framework
for the channel assignment problem in time, frequency,
and code domains is proposed. The unified (T/F/C)DMA
algorithm consists of labeling and coloring phases. Using the
graph theory solutions, channel assignment problems in heterogeneous
network structures have been addressed. Although
this work provides the fundamental theoretical results for
channel assignment in (T/F/C)DMA networks, the framework
is not applicable to the existing network structures where the
channel assignment principles have already been decided. The
application of this framework requires major modifications in
the NG wireless network components.
Resource-Space
We model the resource in a three-dimensional resource-space
with time, rate, and power dimensions as shown in Fig. 3.1 The
three dimensions of the resource-space are as follows:
1) Time Dimension: The time dimension models the time required
to transfer information.
2) Rate Dimension: The rate dimension models the data rate
of the network. Thus, the capacity of different networks
with the same connection durations but different data
rates are captured in the rate dimension. Furthermore, the
bandwidth increase due to the multi-code transmissions
or multi-channel communication is also captured in this
dimension.
THE VIRTUAL CUBE CONCEPT
NG mobile terminals will encounter different access schemes
during accessing different networks within the NG wireless architecture
as shown in Fig. 1. Hence, different resource allocation
units such as CSMA random access, TDMA time slots,
NETWORK MODELING
The Virtual Cube concept introduced in Section III forms a
basis for modeling different access schemes. Based on the Virtual
Cube concept, the underlying access schemes are modeled
as a three-dimensional structure called resource bin. Each dimension
of a resource bin defines the number of virtual cubes
that can be filled in that dimension as shown in Fig. 4, where it
is shown that VPCs, i.e., gray cubes, are used to model the additional
power requirement of the network, while VICs, white
cubes, model the available capacity in the network.
[attachment=22698]
INTRODUCTION
NEXT GENERATION (NG) wireless networks are expected
to provide mobile users with a freedom of roaming
between diverse set of wireless architectures as shown in Fig. 1.
Since an NG wireless terminal will operate in these various
types of networks, the Medium Access Control (MAC) layer
will encounter different protocols that are already deployed in
the access points (AP) of these networks.
RELATED WORK
There exist several studies in the literature to address the
integration of existing wireless systems. In [19], a unified framework
for the channel assignment problem in time, frequency,
and code domains is proposed. The unified (T/F/C)DMA
algorithm consists of labeling and coloring phases. Using the
graph theory solutions, channel assignment problems in heterogeneous
network structures have been addressed. Although
this work provides the fundamental theoretical results for
channel assignment in (T/F/C)DMA networks, the framework
is not applicable to the existing network structures where the
channel assignment principles have already been decided. The
application of this framework requires major modifications in
the NG wireless network components.
Resource-Space
We model the resource in a three-dimensional resource-space
with time, rate, and power dimensions as shown in Fig. 3.1 The
three dimensions of the resource-space are as follows:
1) Time Dimension: The time dimension models the time required
to transfer information.
2) Rate Dimension: The rate dimension models the data rate
of the network. Thus, the capacity of different networks
with the same connection durations but different data
rates are captured in the rate dimension. Furthermore, the
bandwidth increase due to the multi-code transmissions
or multi-channel communication is also captured in this
dimension.
THE VIRTUAL CUBE CONCEPT
NG mobile terminals will encounter different access schemes
during accessing different networks within the NG wireless architecture
as shown in Fig. 1. Hence, different resource allocation
units such as CSMA random access, TDMA time slots,
NETWORK MODELING
The Virtual Cube concept introduced in Section III forms a
basis for modeling different access schemes. Based on the Virtual
Cube concept, the underlying access schemes are modeled
as a three-dimensional structure called resource bin. Each dimension
of a resource bin defines the number of virtual cubes
that can be filled in that dimension as shown in Fig. 4, where it
is shown that VPCs, i.e., gray cubes, are used to model the additional
power requirement of the network, while VICs, white
cubes, model the available capacity in the network.