Cobham Wireless, formerly Aeroflex wireless business unit, has announced that the TM500 network tester family is helping mobile operators to accelerate the deployment of high capacity networks.
Already supporting key LTE-A features such as carrier aggregation of two and three component carriers, TDD/FDD carrier aggregation, and eICIC, the TM500 now also supports Coordinated Multipoint transmission/reception (CoMP), a major feature of 3GPP LTE-A Release 11.
Where carriers are deploying small cells, they often do not deliver the expected user experience and this is slowing HetNet deployment. One of the primary reasons for users seeing a degraded quality of service with HetNets is poor cell-edge performance due to the lack of traffic coordination and interference management between small cells and macrocells.
The Cobham Wireless TM500 is already addressing cell-edge interference issues with eICIC (Enhanced Inter-cell Interference Coordination), empowering mobile network operators to achieve better overall network capacity. With the addition of CoMP it will go one step further, by coordinating transmission and reception between different transmitting and receiving cells.
It achieves this through the use of load balancing, coordinated scheduling, and the management of signal power and interference. In the downlink, each mobile terminal sees improved data throughput, especially near the cell edges, due to reduced interference and an increase in received power.
Similarly, for the uplink, received signal quality and cell edge coverage is improved by simultaneous coordinated reception from different receiving points on the network side.
“CoMP offers enormous benefits to network operators, but it is very challenging both to configure and to validate,” said Nicola Logli, product manager at Cobham Wireless. “It requires tight synchronisation among multiple transmitting and receiving points. The TM500 network tester can emulate and validate realistic CoMP usage scenarios in both uplink and downlink.
“It enables operators and vendors to perform lab and field trials incorporating realistic performance tests for this powerful new LTE-A feature. This helps them maximize throughput in their HetNet deployments, and improve user experience under challenging cell edge and interference conditions.”
More about CoMP protocol testing
CoMP requires the rapid exchange of information, and the coordination of shared and centralized processing between multiple transmitting points. These can include eNodeBs, remote radio heads (RRH) and small cells.
CoMP is both time-critical and computationally intensive, with reports from each user terminal needing to be processed for different points in order to make centralized decisions on scheduling and load balancing.
These decisions then need to be rapidly executed to adjust the configuration and the number of points that are active at any time, based on instantaneous channel and interference conditions.
The Cobham Wireless TM500 network tester provides decoding of received downlink signals from multiple transmission points to test the CoMP algorithms under inter-cell interference conditions. It also allows testing of the decoding of the new Transmission Mode 10 (TM10) from multiple points, and of the newly-introduced DCI format 2D.
For the uplink, it provides multi-point reception testing from multiple mobile terminals in parallel. Each link simulates independent channel conditions. This allows it to validate the uplink CoMP algorithms for distributed reception, with different channel quality at each terminal.
A full protocol log is available for debugging of Radio Resource Control (RRC) messages and configuration. A test feature suite is provided for functional testing, including over-the-air (OTA), different modes of operation, manipulation of messages, overriding network parameters, logging, and scripting.