1. 802.19 Tutorial – Use Case Draft 1
May 2010
doc.: IEEE yy/xxxxr0
July 2010
Tutorial – Use Case Draft 1
Date:
Authors:
Notice: This document has been prepared to assist IEEE It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein.
Alex Reznik (InterDigital)
Tuncer Baykas, NICT

2. Abstract Draft of my tutorial slides for July tutorial
For discussion by the group
Alex Reznik (InterDigital)

3. Coexistence in TVWS: What is it?
July 2010
Coexistence in TVWS: What is it?
TVWS presents a complex regulatory environment
Licensed devices: allowed to use the spectrum whenever, following appropriate rules
Unlicensed devices: permitted to use the spectrum when it is not occupied by licensed devices
Licensed and unlicensed devices do not coexist
Licensed devices make no special allowances for unlicensed devices
Unlicensed device must “protect” licensed operation by regulation
Protection of licensed devices is a medium access problem
Thou shall not access access spectrum when these guys are around
Alex Reznik (InterDigital)

4. Coexistence in TVWS: So what is it then?
July 2010
Coexistence in TVWS: So what is it then?
Coexistence happens between peers
In TVWS, these are unlicensed devices and networks
Not mandated by regulations
Impetus must come from mutual benefit consideration: higher spectrum efficiency for all involved
Why do they need to coexist
Once available channels are known, the various networks and users need to decide – who goes where
This cannot be static – channel availability will change
Who specifies how this can be done
Some (not all) standards specify how different networks using same technology coexist
802.11, do this
Do they do it well??
Some standards don’t even do that
cellular standards do not specify how different operators use the same spectrum
No MAC/PHY standard specifies how other MAC/PHY standards should behave
Nor should one MAC/PHY do it – it would rule over all the others
This void is filled by standards such as in TVWS
Alex Reznik (InterDigital)

5. The Coexistence Problem: #1
July 2010
The Coexistence Problem: #1
“… you know you could help me out here. If you are on WiFi, if you could just get off…”
“… we figured out why my demo crashed. Because there are 570 WiFi base stations operating in this room…”
Steve Jobs
see e.g.
So many talkers …
… and no common language to discuss sharing
Alex Reznik (InterDigital)

6. The Coexistence Problem: #2
July 2010
The Coexistence Problem: #2
802.11
Bluetooth
So little spectrum …
So many ways to use it …
802.22
802.11
How we addressed in ISM bands
“Smart hopping” by Bluetooth
More robust (lower) bit rate by WiFi
“Autonomous” approaches may not work in TVWS
Much larger dynamic range in power (4W / 100 mW / 50mW / 40mW)
Potentially incompatible medium access techniques
Alex Reznik (InterDigital)

7. The Coexistence Problem :#3
July 2010
The Coexistence Problem :#3
Source: Mishra and Sahai, IEEE Comm. Letters, 2009
Few people – many channels …
Many people – few channel …
Source: Gerami, Mandayam, Greenstein.
Report by Winlab, Rutgers U., 2010
Alex Reznik (InterDigital)

8. Operation in TV Bands: Why Deal With the Headache?
July 2010
Operation in TV Bands: Why Deal With the Headache?
TV Band Spectrum presents unique opportunities and possibilities
Potentially a lot of spectrum
But availability not guaranteed
Excellent propagation characteristics
Cover large distances
Penetrate walls, obstacles, vegetation
So what could this be used for
Find additional bandwidth for data networks (in those areas where TV channels are many)
Offload to free up valuable (licensed) spectrum
Quick and cheap network deployment: cover a large area with few access points and little planning
Cheap spectrum for applications requiring only intermittent communication
Alex Reznik (InterDigital)

9. Example Use Case 1: Rural/Suburban Home/Small Office
July 2010
Example Use Case 1: Rural/Suburban Home/Small Office
Source: Sum et. al., IEEE doc. Scc41-ws-radio-10/5r0, IEEE SCC41 Ad Hoc on WS Radio Usage Models, 04/2010
Alex Reznik (InterDigital)

10. Example Use Case 1: Rural/Suburban Home/Small Office
July 2010
Example Use Case 1: Rural/Suburban Home/Small Office
Potential Uses
Device-to-Device (Machine-to-Machine)
WLAN Access
Backhaul
Cellular offload
Characteristics
Single operator controls much of the network and controls the space
Limited interference from like networks
Requires high data rates/no critical usage applications
Is this a good fit for white spaces
Yes, if the channels are available
Yes, if the operator (home owner) can automate the channel selection and coexistence of the various technologies he owns
Alex Reznik (InterDigital)

11. Example Use Case 2: Apartment
July 2010
Example Use Case 2: Apartment
Similar usage to the home use case, but very different environment
Multiple operators
Each resident operates own network
No incentive to cooperate/coordinate
WWAN network may be overlayed into this space
Little spatial separation between the operators
Lots of networks crammed into a small spaces
Opens the possibility of the iPhone4 demo problem
Is this a good fit for white spaces
Maybe – but the inter-network coexistence problem will definitely need to be solved.
Source: Paine et. al., IEEE doc /26r4, Whitespace Coexistence Use Cases, 07/2009
Alex Reznik (InterDigital)

12. Example Use Case 3: Utility Grid
July 2010
Example Use Case 3: Utility Grid
Source: Sum et. al., IEEE doc. Scc41-ws-radio-10/5r0, IEEE SCC41 Ad Hoc on WS Radio Usage Models, 04/2010
Alex Reznik (InterDigital)

13. Example Use Case 3: Utility Grid
July 2010
Example Use Case 3: Utility Grid
Potential uses
Collection of metered data
Reporting of aggregated data over the backhaul
SCADA support
Characteristics
Relative low-rate, can deal with intermittent outages
Single network operator, but spanning a large distance
High likelihood of interference with different networks– this interference varies in nature and spectral location throughout the network
Is this a good fit for white spaces?
Absolutely
Covers large areas
Meters may need to penetrate obstacles
Requires only intermittent connectivity
Alex Reznik (InterDigital)

14. Example Use Case 4: Public Safety
July 2010
Example Use Case 4: Public Safety
Source: Sum et. al., IEEE doc. Scc41-ws-radio-10/5r0, IEEE SCC41 Ad Hoc on WS Radio Usage Models, 04/2010
Alex Reznik (InterDigital)

15. Example Use Case 4: Public Safety
July 2010
Example Use Case 4: Public Safety
Potential Usage
Rapid deployment of emergency personnel networks
Inter-personnel communication
Network backhaul
Communication to the main office
Characteristics
High-rate data rate services
Multi-media and conversational services
Creating an “instant network” where there was none
Is this a good match for white spaces
Yes, IF spectrum can be found, need to have backup plans.
Yes: need to create a network with few APs and no ability to plan
Yes: need penetration through obstacles
Yes: need the reach the main office
Alex Reznik (InterDigital)