1. Transmission Modes for Multi-Radio Access in Hierarchical Networks
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IEEE C80216ppc-11_0015
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Hyukjoon Lee Voice:
Kwangwoon University
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IEEE ppc-11/0005r1 and IEEE L /0058r1
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For discussion in the Project Planning Committee
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2. Introduction
Multi-RAT technologies are widely accepted as a cost-effective alternative to capacity enhancement.
Multiple wireless interfaces are common in newest mobile wireless devices such as smart phones.
IEEE and WCDMA
IEEE and IEEE e
Hierarchical Network is currently being discussed as one of the candidate mobile network technologies for the future.

3. Hierarchical Networks in Multi-RAT Deployment Scenarios
Two multi-RAT usage scenarios are being considered:
Virtual Carrier
Simultaneous communication with both IEEE BS and IEEE AP
Using both IEEE and IEEE connectivity for enhanced spectrum utilization
IEEE traffic offload via IEEE link
Enhanced Tethering (Multi-RAT Client Cooperation)
Using IEEE link to communicate with a multi-RAT helper device
Using both the direct IEEE link and indirect IEEE link to communicate with the IEEE BS for enhanced spectrum utilization
Link switching between direct IEEE and indirect IEEE links
Need to discuss how transmission of data flows can be handled
To propose three transmission modes of data flows

4. Transmission Mode 1: Single-Link Flow
A flow is assigned to either a direct IEEE link or an indirect IEEE link.
Standardized negotiation procedures and IEs for link selection may be necessary
Some criteria
Signal strength
AP/BS load
QoS support
Etc.
Flow 1
Flow 2

5. Transmission Mode 2: Multi-Link Flow
MPDUs belonging to a single flow are distributed among direct IEEE link and indirect IEEE link for enhanced spectrum utilization
L2 reassembly function needed
Use of IEEE address structure/L2 tunneling
Flow 1

6. Transmission Mode 3: Cooperative-Link Flow
The same MPDUs (may be coded differently) of a flow are transmitted both on direct and indirect links
Repeat diversity
Transmit diversity
Flow 1
Flow 1’

7. There are different ways that flows can make use of multi-RAT links
Summary
There are different ways that flows can make use of multi-RAT links
Proposed three transmission modes:
Single-link flows
Multi-link flows
Cooperative flows
Contribution to update the Study Report?