1. Collaboration between 2.4/5 and 60 GHz
March 2010
doc.: IEEE /0xxxr0
May 2010
Collaboration between 2.4/5 and 60 GHz
Date:
Authors:
Yuichi Morioka, Sony Corporation

2. March 2010
doc.: IEEE /0xxxr0
May 2010
Abstract
60 GHz is by itself a promising technology that will provide multi-Gbps throughput at short range.
The inclusion in TGad of fast session transfer feature opens the door to a convergence between all past and future technologies and to potential improvements
of each technology,
and of the overall home network.
In [3], we have presented a simple solution for fast session transfer which satisfies one of the potential use cases that can be envisioned.
In this proposal, we remind some additional use cases and propose solutions to them, based on various means of collaboration between 2.4/5 and 60 GHz, including an improved fast session transfer.
Yuichi Morioka, Sony Corporation

3. Use case 1 Switch between 2
Use case 1 Switch between 2.4, 5 and 60GHz for STA with a switchable interface in STA
5 GHz coverage is available in the whole home, 60 GHz available in rooms
Stations with only one band active at a given time should perform band selection for all of their flows together
- e.g. AP-STB link either in 2.4/5 GHz band or in 60 GHz band
Band selection may be based on
(a) maintaining coverage with user mobility
(b) dynamically changing channel quality
(c) load balancing between bands
Such use case was largely described in [1] and [2]. A FST solution for single interface devices was proposed in [3].
Slide 3

4. Use case 1: FST with a switchable interface in STA
5 GHz coverage in the overall home
Need to fall back to 60 GHz in case of backhaul saturation
Media server
Fall back to 60GHz in case of 5GHz backhaul saturation
Switchable interface
Single link either at 5 or 60
FTTH
Set-top box AP
WiFi 60GHz ( 1 Gbps)
WiFi 5GHz ( 500 Mbps)
Concurrent dual interfaces
Slide 4
presentation title 4 4

5. Use case 2 Switch between 2
Use case 2 Switch between 2.4, 5 and 60GHz for STA with concurrent dual interfaces
5 GHz coverage is available in the whole home, 60 GHz available in rooms
Stations with multiple bands active simultaneously at a given time can perform band selection for each of their flows separately
E.g. Multiple HD flows between AP and STB either in 2.4/5 GHz band or in 60 GHz band
E.g. 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) more efficient load balancing between bands
Such use case was largely described in [1] and [2]. A FST solution for multiple interface devices is proposed in the next slides.
Slide 5

6. Use case 2: FST with concurrent dual interfaces in STA
5 GHz coverage in the overall home,
60 GHz in some rooms
Load balancing between bands to improve the throughputs and QoS
Media server
Concurrent dual interfaces
Two links, at 5 and 60
FTTH
Flow transfer between interfaces
or bonding of the two interfaces
Set-top box AP
WiFi 60GHz ( 1 Gbps)
WiFi 5GHz ( 500 Mbps)
Concurrent dual interfaces
Slide 6
presentation title 6 6

7. How to perform the fast session transfer
Data transfer using MAC_virtual AP
Compared to [3], we consider now that a STA is associated separately on each band/channel, with the physical MAC address of interface of this band/channel.
We consider also the creation, both in AP and ST, of a new FST virtual MAC sub-layer, with links to all concurrent interfaces,
With one virtual MAC address, which is the only one seen by the network
With a forwarding table to link the interface to each flow of a virtual MAC address
FST virtual MAC
Virtual MAC addr: MAC_virtual1
Forwarding decision
FST
MAC 5
MAC 60
PHY 5
PHY 60
Association with MAC1
Association with MAC2
PHY 5
PHY 60
MAC 5
Physical MAC addr: MAC1
MAC 60
Physical MAC addr: MAC2
FST virtual MAC
Virtual MAC addr: MAC_virtual0 IP
FST STA
Slide 7

8. How to perform the fast session transfer
The FST virtual MAC is responsible for
The selection of the interface used by a STA or by flows from a STA
Modification of the forwarding table (which should by identical in AP and STA) in case of fast session transfer.
This modification can be done based on different criteria (saturation, link failure), and requires the transmission of signal frames (FST trigger frames in [3]).
A FST negotiation should be performed prior to transmissions. A master and a slave should be defined in this negotiation and the negotiation should lead to the direct acceptance of future switches, to suppress the need to provide a response when a switch is requested.
The forwarding of the packets on the selected interface
By simply reading the forwarding table
The link between virtual MAC addresses in FST virtual MAC sub-layer and physical MAC addresses in interface MAC sub-layers.
Slide 8

9. How to perform the fast session transfer
With such an architecture, it is possible to
Perform fast session transfer for all flows of a STA
Only one active interface for power savings, coverage issues or interference reductions
Perform fast session transfer for only some flows of a STA
Better granularity for load balancing algorithms
Perform a bonding of all interfaces
Aggregation of the throughput of all interfaces
In this case, additional functions must be added to the FST virtual MAC
Slide 9

10. Use case 3 2.4/5GHz Assisted 60GHz
May 2010
Use case 3 2.4/5GHz Assisted 60GHz
The use of 2.4/5GHz management to discover, assist training, and schedule 60GHz transmission is a solution to improve the performance of ad at larger range
60G Link assisted by 2.4/5G
Media server
Wifi 60GHz ( 1 Gbps)
Wifi 5GHz ( 500 Mbps) AP
Slide 10
Slide 10

11. 2.4/5GHz Assisted 60GHz - Overview
March 2010
doc.: IEEE /0xxxr0
March 2010
2.4/5GHz Assisted 60GHz - Overview
Beamforming would be the key technology to enhance 60GHz range
However, beamforming could only be functional after discovery and training of the target device
If a/b/g/n can coincide with ad, they can be used to better facilitate 60GHz beamforming
Slide 11
Page 11
Yuichi Morioka, Sony Corporation

12. 2.4/5GHz Assisted 60GHz - Options
Several ways to effectively use 2.4/5GHz frames to assist 60GHz operation were previously proposed in [4]
2.4/5GHz Beaconing
Provide 60GHz service discovery, especially when STAs are out of 60GHz omni range
Share 60GHz Beacon Offset (i.e. TX timing) so STAs can discover when to update beamform information or retrain if necessary.
Provide 60GHz Scheduling Information that can be used to adjust the RX/TX beam-pattern to the intended receiver/transmitter
2.4/5GHz Management Frames assisted 60GHz scheduling
Can facilitate better 60 GHz operation via some frames (e.g. Re-scheduling Frame)
Communicate with all STAs in the BSS via 2.4/5GHz frames; single STA via 60GHz
2.4/5GHz Management Frames assisted 60GHz training
Aid between STAs whose 60GHz training information is not available or too aged
Use frames to initiate 60GHz training procedure
Slide 12

13. Use case 4 Backhaul at 2.4/5GHz, in-room 60GHz
It will not be possible to cover entire home with a single 60GHz network
60 GHz should be used to provide intra-room ultra-fast connections.
 In room 60 GHz improves the link reliability and the link robustness in the presence of interferences
2.4/5 GHz should be used to provide inter-room connections
2.4/5 GHz should be used as well as intra-room connections in case of mobility where a 60GHz link would not be maintained
Slide 13

14. Use case 4 Backhaul at 2.4/5GHz, in-room 60GHz
Media server
60G P2P setup with 2.4/5G AP
WiFi 60GHz ( 1 Gbps)
WiFi 5GHz ( 500 Mbps)
Slide 14

15. 2.4/5GHz DLS of 60GHz P2P Simple extension of TDLS
2.4/5 GHz manages setup procedure, and 60 GHz provides a multi-Gbps direct link
Discovering TDLS capable STAs in the same BSS is easy because 2.4/5 GHz has a wider and omni directional range AP
STA1
STA2
DLS setup request
DLS setup response
2.4/5G
60G
Direct link
Slide 15

16. Setup signal flow of 60GHz P2P
Device discovery and beamforming training could be started with 2.4/5GHz signaling.
DLS setup
request
DLS setup
response
60GHz
2.4/5GHz AP
60GHz
Training
Frame
Waiting
for
Response
Beamformed Data
60GHz
2.4/5GHz
STA1
DLS setup
request
60GHz
2.4/5GHz
STA2
DLS setup
response
Waiting for
Training
Frame
60GHz
Training
Feedback
Slide 16

17. March 2010
doc.: IEEE /0xxxr0
May 2010
Conclusions
Collaboration between the 2.4/5 and 60 GHz bands would enable user expectations for ad to be met
Fast session transfer seamlessly provides both the wide coverage of WLAN and the very high throughput of 60 GHz when available
FST can improve the home network by allowing joint management of multiple bands (2.4/5 and 60GHz)
2.4/5 GHz assisted 60 GHz enhances the 60 GHz range by improving discovery and assisting training and scheduling of 60 GHz transmission
2.4/5 assisted DLS of 60 GHz permits 60 GHz to be used for in-room ultra-fast connections while 2.4/5 provides inter-room connections and manages 60 GHz links
We believe that these solutions would improve the overall home network
Slide 17
Slide 17
Page 17
Yuichi Morioka, Sony Corporation

18. Straw polls Yes: , No: , Abstain:
March 2010
doc.: IEEE /0xxxr0
May 2010
Straw polls
Do you support inclusion of Fast Session Transfer, as described in 10/492r0 in the TGad draft amendment?
Yes: , No: , Abstain:
Do you support inclusion of 2.4/5 GHz assisted 60 GHz, as described in 10/492r0 in the TGad draft amendment?
Do you support inclusion of 2.4/5 assisted DLS of 60 GHz, as described in 10/492r0 in the TGad draft amendment?
2.4/5 assisted DLS of 60 GHz
Slide 18
Page 18
Yuichi Morioka, Sony Corporation

19. Reference [1] J. Benko et al, “5-60 GHz use cases”, 802/11-09-0835r0
March 2010
doc.: IEEE /0xxxr0
May 2010
Reference
[1] J. Benko et al, “5-60 GHz use cases”, 802/ r0
[2] L. Cariou et al, “Fast Session Transfer use cases”, 802/ r0
[3] L. Cariou et al, “Fast Session Transfer”, 802/ r0
[4] Y. Morioka et al, “802.11ad New Technique Proposal”, 802/ r2
Yuichi Morioka, Sony Corporation