MEDIEVAL Technical approach
The MEDIEVAL architecture defines four subsystems, namely: the Wireless Access Subsystem; the Mobility Subsystem; the Transport Optimization Subsystem; and the Video Services Subsystem. The Wireless Access Subsystem addresses the heterogeneous wireless technologies (mostly LTE and WLAN) and provides to the upper layers a technology independent, video aware set of functions to steer IP connectivity. The Mobility Subsystem, aiming to cope with the requirements imposed by the sharp video traffic increase and trigger flexible early breakout when possible, provides IP mobility procedures taking into account distributed and dynamic mobility management, IP flow mobility and traffic offload. The Transport Optimization Subsystem provides the measurements tools and the necessary intelligence to perform video traffic engineering across the wireless, access and core network of the mobile operator. It also includes the CDN management optimized for the mobile environment. Finally the Video Services Subsystem leverages the novel interface with the network elements to derive the necessary information to best adapt service delivery to the end user. The key challenge is the design of such interface to enable the mobile operator to satisfy QoE requirements thus minimizing the impact of alternative Over The Top (OTT) services. Currently, the four subsystems of the MEDIEVAL architecture and their interfaces have been completely specified, and the internal design of each subsystem has been partially specified. The subsystems of the architecture along with their interfaces are depicted in the following figure.
The MEDIEVAL architecture has been designed as an evolution of the
current architectures, in particular 3GPP, focusing on heterogeneous
access, mobility and QoE-driven video distribution. In addition,
MEDIEVAL assumes a common core network for both fixed access and
cellular access. The design of the MEDIEVAL architecture has been
conducted considering three target video services, which have been
selected following the requirements provided by telecom operators:
- The well known Video On Demand service, traditionally available in DSL networks as part of triple pay services offers, has been integrated in the cellular network by means of smart CDN caching mechanisms. Content management is performed upon user mobility considering unicast distribution models.
- The second target service is the Personal Broadcasting live video. Traditionally offered as an OTT service, this technology has been enhanced in the project to fully leverage the functions offered by the underlying network, in line with the cross layer MEDIEVAL approach. These activities have led to a number of emerging use cases, hereinafter called Personal Broadcasting for Businesses, which have been recently show cased by one of the project operators during an internal workshop.
- The third target service is the Mobile TV service enhanced for greater bit rates (i.e. LTE) and multicast distribution models.