13.5 SAND Message Handling Behaviors for DANEs and DASH clients
26.2473GPPProgressive Download and Dynamic Adaptive Streaming over HTTP (3GP-DASH)Release 17Transparent end-to-end Packet-switched Streaming Service (PSS)TS
13.5.1 DASH client behaviour
3GP-DASH clients supporting one or more of the following SAND modes: (i) ‘Network Assistance’, (ii) ‘Proxy Caching’, (iii) ‘Consistent QoE/QoS’, shall comply with the actions in Table 13-2 in handling of the corresponding SAND messages.
Table 13-2: Normative behaviors on SAND message handling for 3GP-DASH clients
|
SAND Message |
Actions |
Nature |
|
On DaneCapabilities and SharedResourceAllocation supported |
Send SharedResourceAllocation |
Mandatory |
|
On SharedResourceAssignment |
Select Representations to fit in @bandwidth |
Optional |
|
On DaneCapabilities and AnticipatedRequests supported |
Send AnticipatedRequests with ALL future segment requests. |
Mandatory |
|
On DaneCapabilities and AcceptedAlternatives supported |
Send AcceptedAlternatives with ANY future segment requests. |
Mandatory |
|
On MPDValidityEndTime |
If @mpdUrl present, fetch MPD before @validityEndTime. |
Mandatory |
|
Else (@mpd is present by SAND specification), use @mpd as new MPD version when @validityEndTime has passed. |
Mandatory |
13.5.2 DANE behaviour
In a PSS service environment withone or more of the following SAND modes: (i) ‘Network Assistance’, (ii) ‘Proxy Caching’, (iii) ‘Consistent QoE/QoS’, DANEs shall comply with the actions in Table 13-3 in handling of the corresponding SAND messages.
Table 13-3: Normative behaviors on SAND message handling for DANEs in a PSS environment
|
SAND message |
Actions |
Nature |
|
On SharedResourceAllocation |
1. Add client to the sharing strategy |
Optional |
|
2. Update allocation strategy |
Optional |
|
|
3. Send SharedResourceAssignment to clients in the sharing strategy |
Mandatory |
|
|
On AnticipatedRequests |
Cache resources indicated by AnticipatedRequests and send ResourceStatus to signal available resources |
Mandatory |
|
On AcceptedAlternatives |
Send DeliveredAlternatives in case DANE delivers an alternative segment rather than the requested segment |
Mandatory |