Doc.: IEEE 802.11-10/491r2 SubmissionL. Cariou, Orange Labs Date: 2010-04-30 Fast Session Transfer...

doc.: IEEE 802.11-10/491r2

Submission L. Cariou, Orange Labs

Date: 2010-04-30

Fast Session Transfer

May 2010

L. Cariou, Orange LabsSlide 1

Authors:Name Company Address Phone email Laurent Cariou Orange/France

Telecom +33 2 99 12 43 50 laurent.cariou@orange-

ftgroup.com Philippe Christin

Orange/France Telecom

+33 2 99 12 47 93 [email protected]

Sandrine Roblot Orange/France Telecom

4 rue du clos courtel 35512 Cesson-Sévigné, France

+33 2 99 12 45 11 [email protected]

Thomas Derham Orange/France Telecom

Keio Shinjuku Oiwake Bldg. 9F.3-1-13 Shinjuku Shinjuku, Tokyo, Japan

+81 35 312 8563 [email protected]

Ichihiko Toyoda NTT 1-1, Hikarinooka, Yokosuka, Japan


Yusuke Asai NTT 1-1, Hikarinooka, Yokosuka, Japan


Koichi Ishihara NTT 1-1, Hikarinooka, Yokosuka, Japan


Takeo Ichikawa NTT 1-1, Hikarinooka Yokosuka, Japan


Yuichi Morioka Sony Corporation 5-1-12 Kitashinagawa Shinagawa, Tokyo

+81-3-5448-4018 [email protected]

Ted Booth Sony Electronics Inc.

16530 Via Esprillo, San Diego, CA

+1-858-942-8044 [email protected]

Changsoon Choi IHP Im Technologiepark 25, Frankfurt (oder)

+49 3355625 155 [email protected]

Eckhard Grass IHP Im Technologiepark 25, Frankfurt (oder)

+49 3355625 731 [email protected]

Philippe Chambelin

Technicolor 1 Av Belle Fontaine 35576 Cesson Sévigné

[email protected]

doc.: IEEE 802.11-10/491r2


• Collaboration between 2.4/5 and 60 GHz bands allows the 802.11 user experience to be met by seamlessly providing both the wide coverage of WLAN and the very high throughput of 60 GHz when available

• A key merit of 802.11.ad is that it can build on past successful standards– e.g. 802.11a/n/ad system– This will provide many new market opportunities for the 802.11.ad standard

• In [1] and [2] we introduced several use cases dedicated to fast session transfer.• A method of fast session transfer is proposed which enables very fast

transparent switching to deal with user mobility, dynamic channel conditions and to allow joint management of multiple bands

Abstract

May 2010

L. Cariou, Orange LabsSlide 2

doc.: IEEE 802.11-10/491r2


APSet-top box

Use case 1: FST with a switchable interface in STA

Media server

FTTH

Switchable interface

Slide 3

Concurrent dual interfaces

Single link either at 5 or 60

WiFi 60GHz ( 1 Gbps)

WiFi 5GHz ( 500 Mbps)

doc.: IEEE 802.11-10/491r2


APSet-top box

Media server

FTTH

Use case 2: FST with concurrent dual interfaces in STA

Slide 4



Flow transfer between interfacesor bonding of the two interfaces

Two links, at 5 and 60

WiFi 60GHz ( 1 Gbps)

WiFi 5GHz ( 500 Mbps)

doc.: IEEE 802.11-10/491r2


Use cases 1&2: Switch from 2.4/5 to 60GHzor from 60 to 2.4/5GHz

• Band selection for all flows of a station(stations with only one band active at a given time (Switchable interface) or stations with multiple bands active simultaneously at a given time)

– AP-STB either in 2.4/5 GHz band or in 60 GHz band (one at a time)

• Band selection for each flow of a station separately(only stations with multiple bands active simultaneously at a given time)

– Multiple HD flows between AP and STB either in 2.4/5 GHz band or in 60 GHz band– Session transfer of some HD flows in case of saturation of 2.4/5GHz or 60GHz

Band selection may be based on (a) maintaining coverage with user mobility, (b) dynamically changing channel quality, (c) throughput enhancement,(d) load balancing between bands, etc

We believe that this interface convergence will improve the overall home network

In this presentation, we only consider the case 1 with - an AP concurrent dual band- a STA with switchable interface

Slide 5

doc.: IEEE 802.11-10/491r2


Requirements on seamless fast session transfer

• Requirements for speed of a seamless fast session transfer– For video applications:

• 1080p 60Hz => frame every 16.6 ms• Assuming packet loss: latency between 5 and 10 ms

– For VoIP applications: • Maximum acceptable BSS transfer for VoIP roaming is 50 ms

– For gaming applications, distributed storage or contents sharing:• Same constraints as for video

Session transfer should not exceed 5 to 10 msQuite severe constraint: needs to be better than 11r

• Other requirements– Switch should be able to be initiated by either device in a link (AP or STA)

Slide 6

doc.: IEEE 802.11-10/491r2


How to perform the seamless fast session transfer

BSSIDSSID

Encryption keyAID database

BSSIDSSIDEncryption keyAID database

AID1BSSIDSSIDEncryption key

AID1BSSID

SSIDEncryption key

f

5GHz

f

5GHz 60GHz

• Example scenario:– One AP working at both 60 GHz and at 5 GHz

• link to TV at 5GHz (red)

• link to laptop at 60GHz (blue) to be switched to 5GHz

Slide 7

5 GHz 60 GHz

doc.: IEEE 802.11-10/491r2


How to perform the seamless fast session transfer

• Required functions for FST:

Preparation phase: – Exchange of FST capabilities and FST negotiation for each link prior to transmission.

• We believe the negotiation should lead to the direct acceptance of future switches, to suppress the need to provide a response when a switch is requested

– Sharing of the association parameters between the two bands• To speed up the process by removing the need for disassociation/re-association during the switch

– Definition in STA of a unique logical MAC address, switchable from one interface to another

FST phase (phase during which FST can be done): – Report request/response on one band/channel of particular metrics (such as the load and SNR) of the

other band/channel– Triggering of the session transfer by the transmission of a signal frame

• No need for a response to the trigger frame because of the prior negotiation• No need for disassociation/re-association because of the sharing of association parameters

Slide 8

doc.: IEEE 802.11-10/491r2


How to perform the seamless fast session transferSharing of association parameters (1/2)

• Split between association function and forwarding function– Association to an AP, independently of the current interface/band:

• Negotiation of MAC parameters (security, power save, ….)

• Reception of a unique AID, whatever the band/channel

Slide 9

doc.: IEEE 802.11-10/491r2


ff

BSSIDSSID

Encryption key

BSSIDSSIDEncryption key

AID1BSSIDSSIDEncryption key

AID2BSSID

SSIDEncryption key

Association parameters match

BSSIDSSID

Encryption keyAID database

How to perform the seamless fast session transferSharing of association parameters (2/2)

Trigger signal frame

Slide 10

doc.: IEEE 802.11-10/491r2


How to perform the seamless fast session transferForwarding (1/2)

common MACMAC 60MAC 5

PHY 5 PHY 60

PHY 60PHY 5MAC 5Physical MAC addr: MAC1

MAC 60Physical MAC addr: MAC2

Logical MAC addr: MAClog0

IPIP addr linked to the unique logical MAC addr: MAClog0

MAC 60MAC addr: MAC_ad0

PHY60

AP

FST STA

11ad STA

• Definition in FST STA of a unique logical MAC address, switchable from one interface to another

• Definition in AP of a common MAC with a forwarding table indicating the active interface of a FST STA

MAC addr

MAClog0 5GHz

MAC_ad0 60GHz

doc.: IEEE 802.11-10/491r2


• Definition in FST STA of a unique logical MAC address, switchable from one interface to another

• Definition in AP of a common MAC with a forwarding table indicating the active interface of a FST STA

How to perform the seamless fast session transferForwarding (2/2)

common MACMAC 60MAC 5

PHY 5 PHY 60

PHY 60PHY 5MAC 5Physical MAC addr: MAC1

MAC 60Physical MAC addr: MAC2

Logical MAC addr: MAClog0

IPIP addr linked to the unique logical MAC addr: MAClog0

MAC 60MAC addr: MAC_ad0

PHY60

AP

FST STA

11ad STA

MAC addr

MAClog0 60GHz

MAC_ad0 60GHz

doc.: IEEE 802.11-10/491r2


How to perform the seamless fast session transferTrigger the switch by a signal frame (1/3)

• The trigger signal frame should provide the information to localize the destination band and to indicate which station the switch concerns

• FST signal frame needs to include– The channel number from the destination channel

– The BSSID of the destination band

– The AID of the station that will switch band

Slide 13

doc.: IEEE 802.11-10/491r2



• Additional information in FST signal frame to speed up the FST

– Option 1: include the capabilities of the destination channel in the FST signal frame

By doing this, the station does not need to wait for the next beacon once arrived in the destination band in order to get the capabilities

This will be very efficient for destination bands/channels working with CSMA-CA (ex: from 802.11ad to 802.11n or 802.11ac): very low FST duration

However, for TDMA-based destination bands/channels like 802.11ad60 GHz, the station will anyway need to wait for the next beacon to be informed a) of the next contention-period to request a reserved slot b) of its reserved slot, if a slot has been pre-reserved

Slide 14

doc.: IEEE 802.11-10/491r2



• Additional information in FST signal frame to speed up the FST

– Option 2: use the principle of the "channel switch announcement frame" to plan the arrival in the destination band just before the beacon transmission

• signaling of the destination band/channel TBTT in the FST signal frame

• in addition, the switch can be planned using the "channel switch announcement element" field in the FST signal frame

By doing this, the station will directly receive the capabilities and the contention-period time in case of TDMA.

This will be very efficient for all destination band/channels working with either CSMA-CA or TDMA

Slide 15

doc.: IEEE 802.11-10/491r2


Seamless fast session transfer performance

• Speed of the FST– When using option 2, the FST switch time easily satisfies the 5 to 10 ms

switching requirements• FST duration only includes the time needed to perform the switch and the

reception of the beacon on the destination band/channel

• Trigger of the FST by the AP• Trigger by a FST signal frame

• Such a decision requires a report on one band/channel of particular metrics (such as the load and SNR) of the other band/channel

• Trigger of the FST by the station• The FST can be instantaneous thanks to UL data transmission in the new band

Slide 16

doc.: IEEE 802.11-10/491r2


• Fast session transfer is a very important feature to improve home network by allowing the joint management of multiple bands, and to open new market opportunities.

• To be efficient, FST needs to be seamless and triggered by either one or the other device of a link and to be as fast as 5 to 10ms.

• We proposed to share the association parameters and a new trigger frame that enable such an efficient FST.

Conclusions

May 2010

Slide 17Slide 17

doc.: IEEE 802.11-10/491r2


Reference

May 2010

Slide 18

• [1] “5-60 GHz use cases”, 802/11-09-0835r0

• [2] “Fast Session Transfer use cases”, 802/11-10-0134r0

• [3] “Collaboration between 2.4/5 and 60GHz”, 802/11-10-0492r0

doc.: IEEE 802.11-10/491r2


Time

Time

TBTT signaled in FST signal frame

FST signal frame

FST Switching instant

How to perform the fast session transferTrigger the switch by a signal frame

Slide 19

FST switch duration << 5ms

Doc.: IEEE 802.11-10/491r2 SubmissionL. Cariou, Orange Labs Date: 2010-04-30 Fast Session Transfer...

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