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NSN claims it could double voice capacity on HSPA
Published: 13 May, 2009
Tags >> Nokia Siemens Networks | HSDPA
The main operator concern of the past few years has been expanding the amount of data that a wireless network can support, but voice remains a cash cow and the most used application, and many vendors are looking at ways to deliver this more efficiently too. While the 3GPP struggles with the issue of carrying voice over LTE - or handing it off seamlessly to older networks - the more urgent requirement is to run voice as efficiently as possible on 3G, so that more capacity is freed up for data. Nokia Siemens (NSN) is the latest to demonstrate a response to this challenge, using a technology that has not previously been demonstrated live.
The technology, 'Circuit Switched Call over HSPA' (CSoHSPA), could potentially double the baseline voice capacity on HSPA, says NSN. The vendor worked with Finnish operator, and favorite Nokia guinea pig, Elisa, to carry out the world's first live trial call using the emerging technology. This was run in Elisa's live 3G network using R&D prototype devices supplied by Nokia.
Instead of carrying each voice call over a dedicated voice call as in circuit switched GSM, the new approach is the latest to make use of HSPA's packet-based transport channels, in this case to carry voice. The CSoHSPA technique, when supported by the continuous packet connectivity (CPC) features of 3GPP Release 7, is not only more efficient on the network, but uses less battery, providing up to twice the talk time at the handset end. The efficiency of the technique also means call set-up times can be halved, claims NSN, and operators gain far higher voice capacity per carrier. By making voice over 3G optimal for users and carriers, 2G switch-off could become a viable option at an earlier stage for some cellcos.
To enable CSoHSPA in existing 3G networks, no changes are necessary to the core and a software upgrade in the RAN. The technology is part of 3GPP Release 7 or HSPA+, and so will be adopted by other vendors, though NSN has been the most enthustiastic so far. The firm is making something of a speciality of focusing on efficient voice, and is also pushing its own approach to the voice over LTE conundrum, named Volte. Other companies that have been prominent lately in improving voice efficiency in order to reduce reliance on 2G, while still freeing up data capacity on 3G, have tended to be focused on CDMA - notably recent Qualcomm's doubling of channel capacity on 1xRTT, and ZTE's work on this issue for CDMA and the TD-SCDMA implementation of HSPA
