4G is not about insanely higher speeds

Hilton Tarrant

Hilton Tarrant is production editor at Moneyweb. He also project manages new website launches for the company and covers ICT issues, chiefly through his weekly...

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Right now, there is a lot of hype about “4G”. Cell C, for example, keeps arguing incorrectly that it’s building out a 4G mobile data network.

South Africa’s third-largest operator is investing R5bn together with Chinese equipment maker ZTE in rolling out a network capable of speeds of up to 21Mbps (megabits per second).

This is nowhere close to 4G, despite what Cell C says. This HSPA+ (evolved high speed packet access) network is 3.75G, and is not LTE or WiMAX, technologies commonly associated with 4G. Vodacom and MTN have been quick to respond by provisioning certain areas of their networks with HSPA+.

To put this in perspective, 3G is the base technology, HSDPA (High Speed Downlink Packet Access) is a step up (and sometimes called 3.5G), while HSUPA (High Speed Upllink Packet Access) is the next step up (3.6G) and offers higher uplink speeds. The highest standard defined so far is HSPA+ and has been colloquially dubbed “3.75G”.

4G, the fourth generation of wireless standards, takes two paths. For GSM operators, the upgrade path is on LTE (long-term evolution). LTE has a theoretical maximum download speed of around 100-150Mbps (upload of approximately 50Mbps). Tests using multiple channels have achieved higher speeds than these.

Mobile WiMAX is the other path, but the technology is different from existing 3G on GSM, so the installed base is tiny in comparison. Advocates of LTE point to this as the reason why LTE will dominate the landscape in the coming years.

Vodacom’s Andries Delport agrees, saying that currently around 300m subscribers use 3G technology, while WiMAX only has around 4m.

But 4G is not about insanely high speeds. Vodacom Group CEO Pieter Uys argues that the higher speeds will offer “as many people access to as close a broadband experience as possible”.

Right now, 3G bandwidth (around 7.2Mbps in metro areas) is “shared” between active users. Sure, there are bottlenecks (such as international connectivity, and the largely Telkom-provided links between cellphone towers and the core network), but even without these restrictions, the frequencies, by definition, are shared between active users.

Uys says that the operator’s plans to upgrade to LTE has nothing to do with “selling technology” to customers.

To offer better bandwidth, in other words for you and I to have a faster experience, operators have three options, says Uys.

Firstly, they can lobby regulators (Icasa) for more spectrum. Otherwise, they can simply build more base stations to offer coverage with greater density, a very expensive exercise. Third, they are able to leverage newer technologies – which they are doing.

Newer devices offer greater signal processing within the actual phones, which helps too.

Beyond this, Vodacom is also hoping to use a lower frequency to achieve better 3G coverage through buildings.

Right now, it’s using 2100Mhz (2.1Ghz) for UTMS/3G services, but wants to rollout services in the 900Mhz band.

Uys says that the 700 and 800Mhz bands are ideal but this spectrum is currently tied up in broadcast signals. It should be freed up when South Africa migrates to digital terrestrial transmission, but this so-called “digital dividend” process has been delayed.

There is a conflict about which standard to adopt, with government having seemingly abandoned the DVB-T (digital video broadcasting terrestrial) standard. It is likely government will now adopt either the DVB-T2 successor, or else the Japanese version – ISDB-T (integrated digital service broadcasting terrestrial) which has found favour in Brazil.

Vodacom will also be applying for the 2.6Ghz spectrum being auctioned by Icasa.

“LTE is not about the fastest speeds, but rather about more capacity,” says Uys, beating the drum. He argues that it’s about offering “proper” broadband to more people. Uys would like to see the average user experience (consistent) speeds of around 1Mbps.

Here’s hoping.

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* Hilton Tarrant contributes to “Broadband”, a column on Moneyweb covering the ICT sector in South Africa. If only Icasa could sort out the spectrum mess today…