Broadband Access: Wireline and Wireless - Alternatives for Internet Services

17Fourth Generation Systems: LTE and LTE-Advanced

17.1 Introduction

Following the natural progression that was seen in wired broadband access, where voice-centric connections were succeeded by wide-bandwidth connections with voice being just another service, LTE was developed as a true mobile broadband access technology to support generic always-on broadband access. As such, unlike the UMTS architecture, where voice is carried over an explicitly designed circuit-switched portion of the network, the LTE architecture is designed only for packet-switched services, with voice carried as Voice over Internet Protocol (VoIP). Furthermore, all LTE networks to date have been deployed as an overlay to the existing UMTS/HSPA and CDMA2000 networks, providing only generic data services, with mobile voice calling still relying on the underlying UMTS CS technology. This is a clear testament to the explosion in demand for data and the shrinking bandwidth consumed by voice as a proportion of the data consumption. Major operator-managed voice-over-LTE (VoLTE) roll-outs are only expected in 2014, more than three years after LTE data services were turned on.

17.1.1 LTE Standardization

Following the successful development of global standards for GSM and UMTS under the auspices of the 3GPP, the standardization process for LTE was kicked off at the RAN Future Evolution Workshop in Toronto in November 2004. Several operators and equipment vendors from around the world presented their views on the ...