Nokia Siemens Networks presents HSPA+ and LTE in Vienna

The HSPA+ mobile was able to pass up to 9.7 Mbits/s to the notebook.

In Vienna on Thursday approximately 10 Mbits/s were transmitted for the first time wirelessly via HSPA+ (High Speed Packet Access + also known as HSPA evolved or I-HSPA). Nokia Siemens Networks (NSN) carried out this premiere at the headquarters of Mobilkom Austria. UMTS successor LTE (Long Term Evolution) was also presented in Austria for the first time. The presentation involved sending and receiving a high resolution video at a consistent speed of more than 32 Mbits/s.

For the demonstration of HSPA+, a commercially available NodeB (Flexi Multimode BTS) with integrated radio network controller (RNC) was used as a transmitter. The receiving end was a mobile phone prototype placed in a small protective box together with the transmission aerial. The mobile was used as a modem for a laptop. The demonstration involved the transmission of a video at an average speed of 8.9 Mbits/s peaking at 9.7 Mbits/s. This value is very close to the respective technologies' theoretical maximum speed of 10.1 Mbits/s. The round-trip time for a 32-byte data packet was about 40 milliseconds. For commercial use, 20 to 25 milliseconds are the target values.

By using 64 quadrature amplitude modulation (QAM), the data rates of HSPA+ can reportedly be increased to 21 Mbits/s. If two aerials are used for both transmitter and receiver (MIMO, Multiple Input, Multiple Output) a potential value of 42 Mbits/s can be achieved. HSPA+ may already be introduced in Austria by Mobilkom Austria next year.

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The commercial implementation of UMTS successor LTE including SAE (Service Architecture Evolution) is likely to take a little longer. First trial networks could be established in 2009, and serial production is scheduled to start in 2010. The proposed standards are currently being evaluated using prototypes by various manufacturers and are due to be adopted towards the end of the year. Dan Warren, director of technology for the GSM Association, expects the first national rollouts of LTE in Japan and possibly in South Korea. So far, no agreement has been reached about the frequencies to be used. Warren says that, while the frequency ranges around 2.5 and 3.5 GHz are potential favourites it is also possible that the 900 MHz frequencies so far used for GSM may be re-allocated. He also doesn't rule out the 700 MHz frequencies, which are becoming available due to the switch from analogue to digital TV. LTE can be used with different bandwidth carriers from 1.5 to 20 MHz.

A signal with a bandwidth of 10 MHz was used in the 2.1 GHz range at 2×2 MIMO in Vienna yesterday. This allowed more than 32 Mbits/s to be transmitted consistently from the two aerials of an eNodeB (evolved NodeB model LTE Flexi Multimode BTS) to the two aerials of a "mobile" receiver within a Faraday cage. At present, the receiver is still a rather bulky box. The round-trip time was between twelve and 18 milliseconds.

The configuration shown is said to have the theoretical capacity to reach up to 86 Mbits/s. If the signal bandwidth is increased to 20 MHz, the potential maximum is 173 Mbits/s. Finally, by doubling the number of aerials to four, for both transmitter and receiver, peak values of more than 300 Mbits/s can be targeted. These values, however, are unlikely to be reached by individual users. Because several users generally share the capacity of a cell site, however, LTE technology could significantly improve the overall capacity and the bandwidth and round-trip times experienced by users.

(Daniel AJ Sokolov)

(trk)