1. IEEE 802.21 MEDIA INDEPENDENT HANDOVER SERVICES
DCN:
Title: New Diagram for Network Enablers for seamless HMD based VR Content Service
Date Submitted: July 02, 2018
Presented at IEEE session #86 – San Diego, California, USA
Authors or Source(s): Dongil Dillon Seo(VoleRCreative), Peter Jeong(JoyFun)
Abstract: This document describe to network status of various VR content service by diagram.

2. IEEE 802.21 presentation release statements
This document has been prepared to assist the IEEE Working Group. 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.
The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE
The contributor is familiar with IEEE patent policy, as outlined in Section 6.3 of the IEEE-SA Standards Board Operations Manual < and in Understanding Patent Issues During IEEE Standards Development
IEEE presentation release statements
This document has been prepared to assist the IEEE Working Group. 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.
The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE
The contributor is familiar with IEEE patent policy, as stated in Section 6 of the IEEE-SA Standards Board bylaws < and in Understanding Patent Issues During IEEE Standards Development

3. Background Information
The purpose of this document is to find a way to minimize the VR sickness.
Out of all factors causing the VR sickness, motion-to-photon latency is considered as this is the only factor that matters to the network.
Maximum tolerable motion-to-photon in VR system is 20 ms.
VR system has some fixed latency from the hardware component such as display
Current commercial HMDs exist in two types
Stand Alone Type
All VR content are either rendered or decoded by the embedded processing unit.
Display Type
All VR content are either rendered or decoded by the external device such as PC or gaming console.
For the purpose of network analysis, we do not consider the Stand Alone type HMDs as no network issue exist here.
The following diagrams include the cases where the Display Type HMDs are used. 3

4. Total Motion-to-Photon Latency ≤20ms
Stand Alone Type
VR System
Total Motion-to-Photon Latency ≤20ms
HMD
Motion
Input
New Image
Output
1ms ⑤ ①
Pixel
Switching
1ms
IMU
90Hz OLED Display 11ms ④
Write Display ② ③
Data Processing Unit
No network latency exist in the connection sections 2 and 3 4

5. Total Motion-to-Photon Latency ≤20ms
Display Type
VR System
Total Motion-to-Photon Latency ≤20ms
HMD
Motion
Input
New Image
Output
1ms ⑤ ①
Pixel
Switching
1ms
IMU
90Hz OLED Display 11ms ④
Write Display ② ③
Data Processing Unit
Network latency exist in the connection sections 2 and 3 5

6. * LAN: wired or wireless * WAN: wired + wireless
Case 1
HMD is connected to a local content server such a PC or a gaming console by a wired or wireless network.
VR content is being rendered or decoded in the local content server and HMD is receiving the VR content through either a wired or a wireless network.
Local Content Server
LAN
HMD
* LAN: wired or wireless
* WAN: wired + wireless 6

7. * LAN: wired or wireless * WAN: wired + wireless
Case 2
HMD is connected to a remote content server such as cloud rendering by wired or wireless network.
VR content is being rendered or decoded in the remote content server and streamed to the HMD.
The remote content server is connected via WAN as the remote content server is located outside of the local area.
Remote Content Server
WAN
HMD
* LAN: wired or wireless
* WAN: wired + wireless 7

8. * LAN: wired or wireless * WAN: wired + wireless
Case 3
This is an extended version of case 1 – more than one case 1 model are connected to the remote server.
HMD is connected to a local server like case 1 and the local server is rendering or decoding VR content and send it back to the HMD.
The remote content server in this case is computing the content sent by the local content network and redistribute the calculated data back to the local content server rather than rendering the content in local store.
Remote Content Server
WAN
Local Content Server
Local Content Server
LAN
LAN
HMD
HMD
* LAN: wired or wireless
* WAN: wired + wireless 8

9. * LAN: wired or wireless * WAN: wired + wireless
Case 4
This is an extended version of case 2 - more than one case 2 model are connected to the remote server.
HMD is connected to a remote server like case 2 and the remote server is rendering or decoding VR content and send it back to the HMD.
Remote Content Server
WAN
HMD
HMD
* LAN: wired or wireless
* WAN: wired + wireless 9

10. * LAN: wired or wireless * WAN: wired + wireless
Case 1
Case 2
Case 3
Local Content Server
Remote Content Server
Remote Content Server
LAN
WAN
WAN
HMD
HMD
Local Content Server
Local Content Server
LAN
LAN
Case 4
HMD
HMD
Remote Content Server
WAN
* LAN: wired or wireless
* WAN: wired + wireless
HMD
HMD 10