Published on January 1st, 2009 | by Arsalan Mir12
Evolution Towards HSDPA
As the world is entering an era of technology convergence, the wireless panorama is changing ‘fast and furious’. The recent convergence of the Internet and mobile radio has also accelerated the demand for “Internet in the pocket” on light, low-cost terminals, as well as for radio technologies that boost data throughput and reduce cost per bit. Mobile networks are now going multimedia, potentially leading to an explosion in throughput from a few bytes for the Short Message Service (SMS) to a few Kbits/s for the Multimedia Messaging Service (MMS), to several 100 kbits/s for video content.
This trend to higher data rates over wireless networks will culminate in the introduction of Third Generation (3G) System UMTS (Universal Mobile Telecommunications System).
High Speed Downlink Packet Access (HSDPA) technology is a cost-efficient upgrade to UMTS systems and promises to deliver performance comparable to today’s wireless LAN services, but with the added benefit of mobility and ubiquitous coverage.
Mobile operators who have invested heavy amounts in existing infrastructure will obviously show reluctance towards deployment of new 3G infrastructure. An extremely flexible expansion and migration strategy along the road to the 3G would be “soft” network evolution that does not render existing installations superfluous.
Investment risks are minimized and competitive positions strengthened through the gradual deployment of technology. Intelligently expanding existing infrastructures is often all it takes to be able to offer new forms of mobile data services in practice quickly and flexibly.
Basically four transmission systems play a role in the evolution from GSM to the Third mobile radio generation (3G), namely:
- HSCSD (High Speed Circuit Switched Data)
- GPRS (General Packet Radio Service)
- EDGE (Enhanced Data Rates for GSM Evolution)
- UMTS (Universal Mobile Telephone System)
The chart below shows the evolution path.
The present network architecture stands on EDGE, it stands for Enhanced Data Rates for Global (instead of “Global”, originally: GSM) Evolution. Based on the GSM standard, EDGE permits faster data rates – and so is intermediate step from GSM technology toward UMTS.
UMTS (Universal Mobile Telecommunication System) is the name given to a totally new performance dimension in mobile radio. UMTS is the cornerstone of what is called the third mobile radio generation (3G) for voice and data communication, both packet and circuit-switched. UMTS employs separate frequency bands so is free from the bottlenecks of GSM systems.
Once UMTS is implemented, it would pave the path for HSDPA (High Speed Downlink Packet Access). HSDPA provides a smooth evolutionary path for the Universal Mobile Telecommunications System (UMTS) networks to higher data rates and higher capacities, in the same way as Enhanced Data rates for GSM Evolution (EDGE) does in the Global System for Mobile communication (GSM) world. HSDPA is primarily implemented in the Node B (identical to a BTS in a GSM network) and the RNC (Radio Network Controller, both are the entities oF UMTS RAN (Radio Access Network).
Advantages of HSDPA
Eventually every UMTS market will see HSDPA deployments – the technology offers operators too much of an edge to be ignored.
Major advantages include:
- Peak data rates of up to seven times higher than those in the most advanced UMTS networks
- A four-fold improvement in network capacity
- Reduced round-trip time between network and terminals
- Sophisticated scheduling allowing favorable allocation of resources
HSDPA’s improved spectrum efficiency enables much faster downstream throughput – between network and terminal – than current UMTS technology. Although the theoretical maximum data transfer speed of HSDPA is 10- 14Mbps, the technology will deliver a 2 – 3Mbps downlink on average. Shared among users in an adequately covered area, this will provide each user with a 300K – 1Mbps downlink, i.e. comparable to current wireless LANs and domestic fixed line broadband.
HSDPA is an extremely cost-effective path to higher data rates and provides more efficient use of valuable spectrum. It enables operators to compete effectively in increasingly converged markets and satisfy the need for enhanced QoS and bandwidth-hungry services in an efficient and cost-effective manner.