Vodacom is currently rolling out WiMax in various major cities with a planned launch date set for the next few weeks. WiMax as a technology has been characterized by a great deal of hype which in turn has created unrealistic expectations regarding throughput and coverage.
The service however offers network operators various advantages including built-in quality of service and a symmetrical bandwidth offering.
Download and Upload Speeds
Vodacom is currently trialing WiMax on various profiles ranging from 128 Kbps to 1024 Kbps. An unlimited profile, allowing for maximum speeds, gives an indication of the true potential of the service, but spectrum limitations will most likely limit the speed of the eventual offerings.
Live testing, performed at Vodacom’s head office in Midrand, showed that the service provides a very stable throughput and impressively low latency compared to 3G and other commercial wireless services.
Using the 1 Mbps profile the download speeds to an internal server flat-lined at nearly exactly the theoretical maximum speed while upload speeds were very constant at just under 1 Mbps.
Download and upload testing to off-net servers in South Africa provided download and upload results of just over 1 Mbps. Similar tests to New York and London showed download speeds of 912 Kbps and 969 Kbps and upload speeds of 414 Kbps and 410 Kbps respectively.
Vodacom pointed out that no network tweaking has been done on the off-net WiMax network yet – something which will most likely result in an improved performance.
On the unlimited profile the average downlink speeds from an on-net server was 6.1 Mbps, peaking at 8.3 Mbps. Off-net testing gave a download speed of 4288 Kbps and an upload speed of 1635 Kbps.
In real world testing conditions – 7.2 km from the base station with line of sight and an external antenna – the performance is equally impressive.
The 1 Mbps profile gave local speed test results of 1004 Kbps and 955 Kbps in the downlink and uplink respectively.
On an unlimited profile these ‘real world’ speeds peaked at 4.1 Mbps, with downlink throughput ranging between 929 Kbps and 2529 Kbps using standard web based speed tests. Using similar testing methods the uplink speeds ranged between 371 Kbps and 1395 Kbps, depending on the server location.
It should be noted that the 7.2 km distance from the base station is considered ‘out-of-range’ by some operators and that superior speeds should be achieved when located closer to the base station.
The most impressive part of the service is however not its throughput but latency. The average on-net latency was 30 ms while off-net latency from Johannesburg to Cape Town was 58 ms.
International ping times to New York ranged between 300 ms and 310 ms, challenging the current latency experienced by ADSL users on unshaped ADSL accounts.
These lower latencies are welcome news to the local online gaming community who will undoubtedly be itching to test the WiMax service.
Initial Vodacom WiMax service offerings will most likely focus on the business market.
Vodacom will initially market the service as a Telkom Diginet replacement service with dedicated speeds ranging between 128 Kbps and 1 Mbps.
There will however also be a more consumer focused best-effort broadband offering which will serve as an ADSL replacement service.
Vodacom’s limited access to WiMax spectrum through iBurst – currently only 15 MHz – means that speeds higher than 1 Mbps are not expected. It is also unlikely that Vodacom will receive WiMax spectrum from ICASA.
Vodacom Business – under which the new WiMax service offering will fall – is set to officially take flight towards the end of the month.