PAGE CONTENTS
Objectives
HENCSAT created a test bed for application of Network Coding to heterogeneous satellite based communication networks. This is relevant since satellite communication increasingly is used as a complementary addition to other radio communication solutions, and there is an opportunity to combine all, rather than select one, or multiple networks.
As about 70% of all Internet traffic is video, HENCSAT is particularly including video and photo communication. Since satellite networks commonly are used for mission-critical communication the focus is further on use of visual communication for information and situational awareness purposes.
Users are expected to be mobile, and networks are assumed to be changing as a function of time and location. Links are expected to have errors and traffic is assumed to be IP-based.
HENCSAT specifically targeted two concreate objectives that were modelled and generalized to cover a broader scope:
- Sending visual information from UAVs using satellite communication in combination with available terrestrial networks.
- Receiving visual data to a convoy of vehicles, or ships, forming a moving cluster where the nodes are interconnected using Wi-Fi and were some or all also are connected to Internet via satellite and/or terrestrial networks.
Challenges
In this project, several key challenges were identified to deliver reliable visual-data communications with network coding:
- Mobility, mean that networks are changing, potentially unpredictably, and thus estimates of capacity and conditions is history.
- Dynamic resource allocation over multiple networks with changing availability, capacity, congestion and packet loss conditions.
- Efficient video compression for highly dynamic networks where minimum capacity may be as low as around 100 kbps if only satellite communication is available and tens of Mbps if several cellular networks are present under best case conditions.
- Selecting Network Coding rates for the conditions in question with different and varying erasure rates
- Optimal use and load of the network taking into account the cost of satellite communication and relevance of the data.
In addition to these challenges the right test bench design was a general challenge.
System Architecture
While the challenges are complex, the basic system architecture is relatively simple:
- UAV scenario:
- Camera connected to computer
- Computer connected to multiple networks.
- Networks connected to Internet and receiving node.
- Convoy Scenario:
- Internet video or other data source
- A cluster of receivers requesting the same data.
- Cluster nodes may have one or more Internet connections
- Cluster nodes are interconnected with a wireless LAN.
The two scenarios are interconnected in the top drawing of this web page.
Plan
The duration of the project was 18 scheduled for months.
The basic planning is shown below.
Current Status
The kick-off of the project was 1st October 2016.
The project is on completed.
