Report: TeliaSonera's LTE network delivers on latency more than speed

TeliaSonera's LTE network in Finland delivered peak downlink speeds lower than the advertised rate, but the carrier performed extremely well on latency metrics, according to tests conducted by UK broadband test specialist Epitiro.

In its launch statements and publicity materials, TeliaSonera indicates that subscribers to its LTE service launched in Finland at the end of 2010 can expect download speeds between 20Mbps and 80Mbps. However, Epitiro's tests didn't register anything like the peak rate suggested by TeliaSonera, or the 100Mbps+ claims of vendors such as Ericsson and Nokia Siemens Networks that provide TeliaSonera's LTE infrastructure equipment.

Instead, top speeds ranged from 42 to 49Mbps, while at the bottom end they dropped as low as 5.6Mbps. However, the average download speed was 36.1Mbps, close to 10 times faster than that measured on TeliaSonera's HSPA network at the same time, and on par with the majority of fixed line broadband services in European markets. Epitiro conducted its tests over a five-day period in March and collected 20,000 LTE data points.

Epitiro also found that both download and upload speeds were more than sufficient for key applications. Indeed, LTE upload speeds averaged 1.7Mbps which meets Skype's recommendations for basic video calling (300Kbps), HD video calling (1.5Mbps) and group video calling (500Kbps).

Another key performance indicator for measuring the success of broadband networks is latency, and TeliaSonera has previouslysaid that latency sells LTE. Epitiro's tests revealed that TeliaSonera's LTE latency times were steady at 23ms, while 3G latency varied between 98ms and up to 189ms. Further examination shows that 4G latency performance was very stable with a maximum recorded time of 38msec, well within the requirements for responsive network applications, and that there was no evidence of LTE speeds dropping during peak periods of the day. This contrasted with latency times for 3G, which were often erratic.

According to Epitiro, fixed line latency measurements are typically about 50ms in leading countries, while latency for 3G networks is typically two to three times slower. This affects the usability of real-time communications and has been a substantial limiting factor in the expansion of mobile services into service areas such as real-time gaming, video calling and even VoIP.

Epitiro also tested Voice over LTE, terminating a call originating in Finland over a Samsung USB device to a test probe on BT's 21CN network, according to a Mobile Europe report. In total, Epitiro, made 334 calls and voice quality was deemed "excellent" for the most part with the exception of a couple of calls where the quality was merely "good." Only a single call had voice quality (upstream) that would be deemed "poor."

Epitiro noted that comparisons with 3G performance could be misleading, since the LTE network does not have as many users as legacy networks and therefore has not been tested under heavy traffic load. Epitiro said it will explore this phenomenon and look to conduct motion tests in vehicles.

For more, see:
- see this release
- see the full report (registration req.)
- see this Mobile Europe report

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