1. Amendment Proposal for TV White Spaces Operation
Month Year
doc.: IEEE yy/xxxxr0
Amendment Proposal for TV White Spaces Operation
Date: April 27, 2010
Authors:
Name
Company
Address
Phone
Eunsun Kim
LG Electronics
Mobile Comm. Lab, LG R&D Complex 533, Hogye1, Dongan, Anyang, Korea
Yongho Seok
Mobile Comm. Lab, LG R&D Complex 533, Hogye1, Dongan, Anyang , Korea
Soonjoon Park
John Doe, Some Company

2. Introduction The technical issues raised in this proposal
Scanning Issue
Slide 2

3. Scanning Number of scanning channels in TVWS
The candidate channels are almost 30 (=180MHz/6MHz) when one channel bandwidth is 5 MHz
Considering 10MHz/20MHz channel bandwidth, the number of channels that STA should scan are tripled (around 90).
Large initial access delay of Passive Scanning
Scanning time might be around 9,000ms
i.e., 3 (Number of candidate bandwidth) x 30 (Number of candidate channels) x 100ms (Beacon Interval)
Power consumption
Power consumption depends on the number of scanning channels
Submission
Slide 3

4. Accelerate Contribution
November 2009
Accelerate Contribution
Scanning
Multi-band mode
STA can use other links and TVWS link as well as a control link to discover AP and get the TVWS MAP information
White Space Map specifies the channel list unoccupied by the primary users
They can be a/b/g/n/cellular link or TVWS link
TVWS MAP transmission
Within beacon frame
Within response frame requested by STA
Can be transmitted in a/b/g/n/cellular or TVWS link
LG Electronics, Inc.

5. Accelerate Contribution
November 2009
Accelerate Contribution
Scanning
Multi-band mode
- Seamless WLAN service
LG Electronics, Inc.

6. Accelerate Contribution
November 2009
Accelerate Contribution
Scanning
Multi-band mode
Coverage difference between other links and TVWS link
Due to carrier frequency characteristics
There are often coverage holes of 2.4GHz WLAN
Relative link budget difference is around 9~12dB (TVWS link vs. 2.4GHz link)
Due to System parameter
TVWS
2.4GHz link
Channel bandwidth
5MHz
20MHz
Guard Interval
3.2us
0.8us
Maximum transmission power
100mW
Relative Power Spectral density 1
0.25
LG Electronics, Inc.

7. Scanning Cold Start mode Warm Start mode
In a very initial state, or after certain elapsed time, in which STAs do not have TVWS channel information, STAs scan whole TVWS channels
Or STAs get TVWS channel information from other than TVWS link
Warm Start mode
STAs scan TVWS channels from the last operation with available TVWS channel list, i.e. warm start mode
STAs need not always scan whole TVWS channels
STAs need not receive control information via 2.4GHz/5GHz link
In a warm start mode, STA shall scan TVWS channels based on TVWS information received from AP during last operation

8. Accelerate Contribution
November 2009
Accelerate Contribution
Scanning
White Space Map Element
Transmission in TVWS is permitted only on channels that are indicated as available
The available channel list is referred to as a White Space Map (WSM)
Includes a list of identified available channels and corresponding maximum allowed transmission powers per available channel
A WSM is generated from database access and may be updated by measurement report
Element ID
Length
(8+2*n)
TV bands database access time
Channel Number 1
Power Constraint 1
...
Channel Number n
Power Constraint n
Octets: 1 8
LG Electronics, Inc.

9. Accelerate Contribution
November 2009
Accelerate Contribution
Scanning
White Space Map Element
Transmission Interval
A MIB variable dot11TVWSMapPeriod is defined
WSM IE is included within at least one transmitted Beacon frame every dot11TVWSMapPeriod beacon interval
WSM valid time
A MIB variable dot11TVWSMapValidTime is defined
WSM IE is valid for a dot11TVWSMapValidTime from the TV bands database access time
LG Electronics, Inc.

10. Accelerate Contribution
November 2009
Accelerate Contribution
Scanning
White Space Map Announcement Frame
Whenever the available TV channel list has been updated
The enabling STA should transmit a correspondingly updated WSM announcement frame
Category
Action
White Space Map element
Octets: 1
variable
LG Electronics, Inc.