With the new DVB-T2 standard, a shift from ASI interfaces to IP interfaces on encoders, multiplexers and transmitters is happening reducing complexity and lowering cost. At the same time a technology shift for radio links driven by the introduction of all-IP 3G mobile networks are changing the interfaces of the radio links from E3/DS3 and STM-1/OC3 to IP radio links. This transforms Digital Terrestrial and Mobile TV networks to all-IP infrastructure. This step imposes new challenges on the IP QoS to handle the mission critical characteristics of national TV distribution. Priority and class based IP QoS targeted to datacom services do not offer sufficient QoS and reliability, and overprovisioning of capacity is not and option in the low capacity environment of radio links.
The Nimbra MSR platform, with its revolutionary IP QoS functionality, is a reliable, high QoS solution for the shift towards all-IP DTT networks already proven in a large number of commercial installations.
Market
The developement of new digital-TV standards and products makes the shift towards all-IP DTT and Mobile TV networks a reality withing the coming years. Early implementations of all-IP national DTT networks are now happening in for example Sweden by the national operator Teracom. Many others investigating all-IP networks when installing new distribution networks or upgrading to second generation DTT network.
Challenges
The challenges when upgrading the terrestrial infrastructure to IP can be summarized as:
- Rapid deployment - New nationwide infrastructure must be deployed in a short time putting requirement on simple, reliable QoS provisioning, capacity planning and node configuration.
- Efficient usage of link capacity - The capacity to the transmitters are limited since they are normally reached with radio links supporting IP radio links with up to 200 Mbps.
- Reliability - National TV distribution is mission critical to governments. These systems require advanced redundancy and disaster recovery schemes to handle network faults.
- Large scale IP multicast - The distribution of the TV signals needs to reach a large number of transmitters with short restoration time in case of failures.
- Multi-Service - To have a fast Return of Investment on the infrastructure, several services are desired to be accommodated in the infrastructure without interfering with the critical TV transport. This is specifically a challenge when mixing distribution, contribution and IT traffic.
- Reliable distribution of time to transmitters - Many installations use Single Frequency Network (SFN) operation. Distribution of accurate time signals (1 PPS and 10 MHz) to the transmitters is crucial for reliable operation.
Net Insight offering
Net Insight’s Nimbra MSR platform is the leading transport solution offering the most reliable transport network for digital TV distribution with state of the art IP QOS functionality. Nimbra MSR is a multi-service IP platform with advanced network management capabilities offering highly automated, plug-and-play operation when deploying large scale networks. Engineers can configure the systems and provision new services quickly and easily.
The Nimbra MSR offers the best link utilization on the market with its guaranteed transport (100% QoS) avoiding the need for overprovisioning to ensure quality.
The Nimbra MSR platform supports advanced network redundancy schemes assisted by an automatic control plane that offers mesh protection and 1+1 protection for IP unicast and multicast. Nimbra also has built in disaster recovery mechanisms for head ends.
Nimbra has an optimized multicast scheme specifically designed for large scale TV distribution. This is assisted by simple point and click configuration and automatic mesh restoration. The multicast distribution forms an optimal distribution tree over any type of topology.
The Nimbra MSR platform is a multi-service platform with built in interfaces for media, datacom and telecom:
- IP based DTT and Mobile TV distribution for DVB-T2 and other standards
- IP based remote management
- Low jitter, no loss IP contribution transport
- JPEG2000/J2K compression for contribution
- L2 VPN services
- FEC based error recovery for unreliable links
- 10/100/1000 Base-X physical ports
The Nimbra platform supports network-based time distribution with built in protection switching. This means that you can distribute highly accurate time signals to the transmitters inband. This eliminates the need for GPS receivers for receiving 1 PPS and 10 MHz signals at the transmitters and removes the vulnerabilities associated with GPS time distribution.
Key Benefits
The major benefits of the Nimbra platform for all-IP DTT networks are:
- State of the art IP QoS mechanisms for mission critical video distribution offering zero packet loss, low jitter transport.
- Mix of digital TV, contribution, IT, VoIP and VPN services offering integration of all services in one platform
- In-band management for remote management of Nimbra equipment and third party equipment at transmitter sites
- Ability to integrate contribution services using compressed and uncompressed signals in the same infrastructure
- Network-based time distribution (1 PPS and 10 MHz) replacing GPS receivers at the transmitters for SFN networks