1. Mobile cooperation usage models
January 2008
doc.: IEEE /0081r1
January 2008
Mobile cooperation usage models
Date:
Authors:
Marc de Courville (Motorola), Frank Fitzek (UoAalborg)
Marc de Courville, Motorola

2. Scoping out 11n enhancements (1/2)
January 2008
doc.: IEEE /0081r1
January 2008
Scoping out 11n enhancements (1/2)
Initial proposed items that we believe deserve consideration for potential inclusion in the PAR:
Import technical IMT-Adv requirements to be sure to address this opportunity, and not to be alienated to external body evolution
WRC’07 result is to aggregate IMT-2000 and IMT-Advanced spectrum into one common pool and IEEE could have access to this band: this is a huge opportunity!
Single link rate is not a suitable metric anymore: aggregated throughput is a better suited one to capture
In every environment more than one device is expected to operate: multi-user diversity is a new area and source of gain to exploit (cf vht, vht)
Spectrum efficiency
>1Gbps in 80/100MHz requires MIMO and sounds feasible (cf vht)
But do not get caught into a very high data rate only standard: still maintain and improve reliability of legacy like rates
MHz
MHz (Region 2 & part of 3)
MHz (Region 1 & 3)
GHz
GHz
Marc de Courville (Motorola), Frank Fitzek (UoAalborg)
Marc de Courville, Motorola

3. Scoping out 11n enhancements (2/2)
January 2008
doc.: IEEE /0081r1
January 2008
Scoping out 11n enhancements (2/2)
Initial proposed items that we believe deserve consideration for potential inclusion in the PAR (con’t):
Below 6GHz spectrum operation
What could higher carrier frequencies bring to .11 WG except what WPAN or IEEE c is addressing?
MAC&PHY features to ease interoperability with WMAN
Wi-Fi and WiMax will be integrated soon in the same chipsets: it opens the door to think beyond silos and go towards cooperation and complementarity!
Better outdoor support:
Wi-Fi is already operating outdoor (Hotspots, 4.9GHz), improved delay spread tolerance is appealing
Talk time constraints
Be competitive with cellular in terms of battery life is key to make handhelds truly adopt Wi-Fi
Enhanced peer to peer capabilities: 11z is a start
Marc de Courville (Motorola), Frank Fitzek (UoAalborg)
Marc de Courville, Motorola

4. Purpose of this presentation
January 2008
Purpose of this presentation
Complement vht WFA usage models to motivate and capture mobile cooperation: 1 usage model, 3 usage scenarios
Marc de Courville (Motorola), Frank Fitzek (UoAalborg)

5. The Architecture and benefits
January 2008
The Architecture and benefits
Architecture based on single but preferably dual mode air interfaces devices
Multiple STAs form a cooperative cluster (CC) using short range 11vht
All or a subset of these devices is connected to an overlay network (Wi-Fi or cellular e.g. 16e/m or LTE)
Main idea: make a cooperative use of resource limited entities such as data rate, energy, processing power, antennas, etc.
Benefit: enhance
Data rate: the CC is accumulating n-times the data rate of a single mobile device with higher diversity and robustness
Battery life: the energy consumption can be reduced by cooperative actions
Processing power: distributed task scheduling with digital video streaming can reduce the energy consumption and complexity
Number of antennas: distributed antenna array leads better exploitation of the diversity which is important for mobiles
Diversity gain: exploiting a new source of diversity, multiuser diversity
Marc de Courville (Motorola), Frank Fitzek (UoAalborg)

6. Usage Model: Cooperative Tx/Rx
January 2008
Multiple users are interested in the same service
Possible applications: Download / Multimedia Streaming / Web browsing
Usage scenarios may be either in Downlink or in Uplink
Benefits: delay, energy, bandwidth
This usage model is instantiated in 3 usage scenarios:
Data download
Multimedia Streaming
Web Browsing
Marc de Courville (Motorola), Frank Fitzek (UoAalborg)

7. Usage Scenarios: Data download Multimedia streaming Web browsing
January 2008
Usage Scenarios:
Data download
In case the CC is interested in the same data (geographic information, mp3 file, etc) each mobile devices is retrieving a portion of the information and exchange it among the CC
Benefits in the delay and energy
Multimedia streaming
In case the CC is interested in the same real time data, the CC offers larger bandwidth and therefore better quality of service
Benefit in larger bandwidth
Energy saving can be achieved depending on technology used (idle power sensitive)
Possible support from network side by preparing cooperation friendly content: e.g. using multiple description coding
Web browsing
If the devices of the CC are using individual traffic such as web, members of the CC support each other to retrieve the information as fast as possible.
Slight increase in energy consumption but smaller delay (ping time)
Marc de Courville (Motorola), Frank Fitzek (UoAalborg)

8. Illustration of gain in Data Download Usage Scenario
January 2008
Energy gain
1 eq. 100%
Energy gain
1 eq. 100%
# users
# users
3G/WLAN
Idle power consumption in WLAN (0.97W) is reducing the gain for two cooperative entities
WLAN/WLAN*
Remarks:
For both scenarios delay decreases inverse proportional with # of cooperating entities
Power values results from Aalborg university measures on mobile devices
Marc de Courville (Motorola), Frank Fitzek (UoAalborg)

9. January 2008
What we can do better in .11vht for implementing such cooperative schemes
Need for simultaneous transmitting devices each capable of 11n rate targeting 1Gbps aggregated throughput
Can be achieved either through flexible bandwidth allocation (OFDMA) or space MAC (SDMA)
Distributed virtual antenna arrays for one antenna transmitting phones
Robust and flexible bandwidth allocation
key for creating small clusters with large bandwidth compared to smaller bandwidth larger range backhaul transmissions: it is at the heart of the battery saving effect
Multiple source aggregation
MAC efficiency has been improved in 11n by introducing aggregation: single destination: AMPDU, AMSDU, multiple destination: PSMP
Still missing multi-source frame aggregation which exploited in the CC can lead to better throughput and delay characteristics
Marc de Courville (Motorola), Frank Fitzek (UoAalborg)