EvDO (Evolution Data Optimized) is a 3G technology and an evolution of 2G CDMA; which can effectively be described as ‘Mobile Broadband’. The technology basically utilizes the cellular channels of the CDMA network to provide broadband internet.
WiMAX on the other hand is falsely (in Pakistan) regarded as a 4G technology. The reason: Of the two standards of WiMAX – FIXED and MOBILE, the former is deployed in Pakistan. Whereas the xG term describes generations of ‘Mobile Networks’. One on his own can validate this by experiencing several connection-resets when moving around in the city with a laptop and a WiMAX connection. EvDO on the other hand will stay connected. (Note that although WiMAX is not mobile, but it certainly is Portable – works everywhere but not on-the-move)
In Pakistan, 3G might be perceiving the nearly-4G moving into its territory at present. But the question is: ‘How deep can it intrude?’.
Although, both EvDO and WiMAX can rightly be called broadband; the latest revised version of CDMA EvDO , ‘Rev. A’ delivers peak download speed of 3.1Mbps with 1.8 Mbps uplink. WiMAX on the other hands can deliver a whooping peak of 5Mbps downlink with 2.4Mbps uplink under ideal conditions. WiMAX operators however do not offer these peak rates. First of all because even the 3.1Mbps link sounds more than enough for an average Pakistani user. Secondly because of the technical (capacity) issues as explained later on.
As far as number of cell sites is concerned, the number of users served by a single WiMAX Base Station (WBS) defines the data rate offered to each user. For instance, if a WBS has total throughput of 70Mbps and 35 users are camped onto it, each will be served with a 2Mbps link (provided that some lower limit such as 512K or 1M is not enforced). In a situation of users increasing beyond prediction, the data rate will decrease. Increase in number of subscribers will ultimately force the WiMAX operator to install new sites, or otherwise the promised quality of service will tarnish. EvDO on the other hand follows a different scenario and number of users swelling beyond prediction will mean the new campers to be deprived of service rather than stealing others’ space.
Moving back to Pakistan, the mobility doesn’t matters much to everybody other than a few on-the-move businessmen, mobile work teams, emergency response teams and mobile fleet vehicles if any; making a maximum 5% of the total wireless broadband users.
Capacity issues are operators’ headache, but means a lot to service provisions. Because of the reasons explained earlier, WiMAX towers are required to be installed at every 1-mile in mild, and sometimes down to a quarter mile in dense urban environments. However both the technologies fit in for rural settings with a maximum airlink range of 10 miles and 20 miles respectively. In this case a single base station of either technology can cover a couple of nearby lying habitations. CDMA operators will however enjoy the infrastructure already deployed for WLL phone service.
Lastly, but most significantly… service cost of an equivalent EvDO package is quite greater than its counterpart. Although the USB devices costs almost the same, CPE however costs much less and is available with WiMAX only. The only disadvantage… CPEs are not pocket-size, and require AC power.
Summarizing the situation; yes, it seems that WiMAX will knock EvDO out in urban environment. EvDO will however rule the rural and remote areas, since the expected low traffic needs can be met by CDMAs’ existing infra. Moreover, the on-the-go and nationally roaming businesses’ choice will still not be WiMAX.
One thing holds great importance to be noticed here. The only active 3G networks (EvDO – By PTCL and Worldcall under the brand names ‘EVO Wireless’ and ‘Worldcall Wireless Broadband’ respectively) in the country are the evolutions of 2G CDMA networks. CDMA networks in Pakistan have never enjoyed the popularity GSM had. Had these 3G networks been the GSM-evolutions (HSDPA/UMTS), the face of market would have been completely different.