Mobile broadband has rapidly become an indispensable tool for many mobile workers who, if they previously wanted to check email or access the enterprise network, relied on finding a Wi-Fi hotspot or plugging into a hotel telephone line.
But with the recent deployment of HSPA mobile broadband services throughout the GSM world, mobile workers are now able to access the internet at multi-megabit speeds at costs comparable to ADSL. HSPA is proving so reliable that for some companies, it is even used as a back-up option for networking branch offices.
In this article we look at exactly what HSPA is, and where mobile broadband is going.
What is HSPA mobile broadband?
High speed packet access (HSPA) is an evolution of 3G/GSM technology. Operators sometimes call HSPA-enabled networks as 3.5G, 3.75G or 3G+ mobile. HSPA is a software upgrade of the network infrastructure, improving the download and upload speeds of the first deployments of 3G. It currently has three versions:
• HSDPA - High Speed Downlink Packet Access - which allows files to be downloaded at (theoretical) speeds of 1.8 Mbps, 3.6 Mbps, 7.2 Mbps or 14.4 Mbps dependent on the software upgrade to the network. In practice a HSDPA 3.6mbps network can download a typical music file of around 3Mbps in 8.3 seconds and a 5Mbps video clip in 13.9 seconds. A list of HSPA networks can be found here
• HSUPA - High Speed Uplink Packet Access - which enhances the upload speeds the network can support. When HSPA first appear, upload speeds were limited to 384 kbps, but have now increased to 5.7 Mbps making it easier to send emails with large attachments. HSUPA is in operation in 61 networks, as of July 2009.
• HSPA+ increases upload and downloads speed significantly, to 42 Mbps and 11Mbps. By using spectrum more efficiently, the GSMA says HSPA+ will lead to higher peak rates, lower latency, faster call set-up times, and significantly longer talk times. HSPA+ is also said to be three times more efficient when running VoIP. This will free-up significant capacity which could then be used to help meet the increased demand for data services. Currently there are 4 networks with HSPA+ in service with a further 25 in deployment, trial or planning stages.
How successful has mobile broadband been?
HSPA subscriber growth has been staggering over the last two years. According to Wireless Intelligence
there were 140 million HSPA mobile broadband subscribers in July 2009, although it should be said that not all of these will be using the mobile broadband capabilities of their HSPA devices.
Key to the development of HSPA mobile broadband has been Asia. According to Ovum, 40% of global mobile broadband subscribers will come from the APAC region
, which includes mature markets like Japan and South Korea, and the expected hotspots, India and China. Globally, Ovum predicts users mobile broadband services will grow from 181 million in 2008 to over 2 billion in 2015, including 258 million users accessing users globally accessing mobile broadband services through laptops connected via USB modems, data cards or those that have embedded mobile modules. Over 13 million netbooks, for instance, with embedded mobile broadband, were sold in 2008, estimates Pyramid.
Informa Telecoms & Media also forecasts a bright future for mobile broadband. The analyst firm predicts that by 2013, mobile broadband subscribers will represent almost one-third of all mobile subscribers
. The mobile broadband boom is being triggered by the combination of widespread mobile broadband network coverage, appealing devices such as USB modems and the Blackberry Storm, and competitive flat-rate tariffs. Key markets will be China, India, Japan, the USA and South Korea.
How is mobile broadband expected to evolve?
The next step in the development of 3G/GSM family of technologies, of which HSPA is a member, is Long Term Evolution (LTE). In early March 2009, the Global Mobile Suppliers Association (GSA)
said that more than 26 network operators globally had committed to LTE deployment and that up to 10 LTE commercial networks are expected to launch in 2010.
LTE is being developed by the 3GPP
as an evolution of GSM/UMTS network technology. It promises much higher data rates for uplink and downlink paths (the 3GPP is aiming for 100Mbps/50Mbps downlink/uplink) although compatible network architecture and technology will be needed. However, the system includes support for a full IP-based network and harmonisation with other radio access technologies including CDMA2000 and mobile WiMAX.
Are there any alternatives to HSPA and LTE?
Mobile broadband is not limited to HSPA: mobile WiMax and EV-DO, both stronger in North America and Asia than they are in Europe, are also considered as mobile broadband technologies, though their subscriber numbers are limited. Accurate figures for WiMax are hard to find, although In-Stat reports that in Q1 2009, there were 9 WiMAX 802.16e networks deployed worldwide, mainly in Asia Pacific and Eastern Europe.
WiMax was originally created as a fixed-line alternative to DSL and cable broadband for areas with poor fixed-infrastructure, a later version of the standard - 802.16e - allowed for mobility. WiMax base stations achieve an aggregate throughput of 30-50 Mbps, but in practice users will have speeds in the order of 2 Mbps symmetrically. Deployed in countries like South Korea, Japan, Pakistan, India, Russia, and the US, mobile WiMax has not kept pace with HSPA. Although defined as 3G, it operates in a different spectrum band entirely (3.5GHz). Informa Telecoms predicts that WiMAX will have 103m subscribers by 2013
, compared to 1 billion using HSPA.
Will there be enough spectrum for the demand for mobile broadband services?
With the rapidly growing demand for mobile broadband services of all varieties, operators will inevitably reach a ceiling within their existing spectrum bands. One of the main hopes for increase their spectrum is the Digital Dividend, which comes from countries switching off their analogue television networks and moving to digital.
At the World Radio Conference
in 2007, governments from Europe, Middle East and Africa agreed that the 790-862 MHz frequency band should be set aside for mobile broadband services once the analogue television networks have been turned off in the next decade.
The Digital Dividend spectrum is of great interest to the mobile industry because it is more efficient that the current spectrum bands (around 1900-2200 MHz). Networks in lower frequency bands are cheaper to deploy because radio waves travel further - and so can support rural communities - and are more efficient at penetrating walls - so can compete more effectively with fixed-line broadband. And with less cell sites required to service a wider area, the operators' savings can be passed on to users.
Another option for fuelling the spectrum demand is refarming: this entails reusing the existing 850/900MHz band occupied by 2G GSM and CDMA services for HSPA or EV-DO. Again, like Digital Dividend spectrum, because it is lower frequency than current 3G bands, less cell sites are needs so it operators will be able to achieve rural coverage. Recently the EU approved the reuse of 2G GSM spectrum for 3G mobile broadband