Carrier Aggregation in 4G LTE and 5G Wireless Network
Carrier Aggregation, which was introduced into mobile networks as part of the LTE-Advanced technology (3GPP release 10), opens new opportunities for mobile service providers to deliver throughput rates never achieved before. This is done by aggregating the traffic from multiple wireless channels – commonly called component carriers or carriers for short – thus adding up the throughput of each of these carriers.
However, if for various reasons one or more of the carriers are not fully utilized by a user's handset – or not utilized at all – the user will experience degraded service. Detecting such an issue is a major challenge for the service provider, since the user is still receiving service and may not even be aware of the problem until he or she tries to use bandwidth-demanding applications.
To speed up the detection of the problem the service provider needs a tool that can sniff and analyze the traffic on the air interface and highlight potential problems on it. For identifying carrier aggregation issues it should check the utilization of the different carriers by any selected handset and provide an indication of the carriers that are used and the status of each.
For deeper troubleshooting purposes the service provider will also need the option to look into the PHY layer and get clear indications which carriers are used at any point in time in the downlink and uplink frames.
To identify the root cause of performance limitations in some carriers and speed up their troubleshooting, he will also need performance indications such as SNR and RSSI individually for each carrier, along with a comparison of these parameters for multiple carriers simultaneously, preferably in a graphical format.
This is exactly the approach that we took in our LTE-Advanced Xpert, which has the above mentioned tools for detecting and troubleshooting carrier aggregation issues, as well as a rich variety of additional tools for troubleshooting issues in the services delivered over their wireless networks.