What Mobile Speeds Really Mean

Note: In deference to more common international terminology, I have switched to using the term Mobile in general references to the 3G and greater cellular wireless systems.

The recent approval of the International Mobile Telecommunications-Advanced or IMT-Advanced technical standards by the ITU once again has raised the spectre of Mobile data transfer speeds and what they really mean. The new specification covers numerous aspects such as standard Internet Protocol (IP) packet switching, scalable channel bandwidth of between 5 and 20Mhz, with 40Mhz channels possible in MIMO (Multiple-In, Multiple-Out) mode. However it is the data rates that attract the most attention.

There are three ways to look at data transfer speeds to come up with a rate:

a. The theoretical maximum. This is the speed achieved under ideal conditions, usually in a test or laboratory situation. The chances of anything approaching these speeds will be achieved in the real, day-to-day world is slim to none. In my estimation, anything approaching 50% of these speeds on a somewhat regular basis would be outstanding.

b. The rates advertised by vendors. This is a very tricky one to get a grip on. The tendency is to over promise and under deliver. While the bold type may indicate an impressive speed, the fine print may well indicate this is under ideal conditions and may vary for each actual user. Another trick is to boldly state the maximum theoretical rate while explaining in the fine print this may be achievable for a supplemented service with an additional fee. A different approach is to quote a high speed with the note that this fantastic speed is only available in selected areas, usually large urban centres like Montreal, Toronto, or Vancouver. The bottom line is that customers should treat any vendors’ quotes for speed with a healthy degree of scepticism.

c. The actual rate Mobile users receive. There are many network variables impact the speed received by the end users. Obviously, the user’s hardware must be compatible with and connected to the matching network hardware. While IMT-Advanced is meant to be backward compatible it is unlikely existing 3G/4G user hardware will be forward compatible. Another major impact is access node (cell site) congestion. Since the network uses shared bandwidth, the greater the number of users, the slower the rate per user. The accumulation of all the factors can be so severe that the speeds received becomes unusable. 

The IMT-Advanced theoretical rates expected are 1 GB for stationary or static situations and 100 Mbps when on the move at fast (highway?) speeds. That is about all that can be said at this time as there is no public information available in the area of advertised rates and actual rates.

However, we can examine the three ways mentioned above as they apply to Long Term Evolution or LTE networks currently operated by Bell and Rogers. A certain degree of caution needs to be exercised due to the restricted coverage area and limited customer base for the existing LTE networks.

The theoretical rates for LTE are 150 Mbps upload and 70 Mbps download.

Based on information on the vendors’ websites, the advertised LTE speeds are:

1. Bell – currently up to 75Mbps with eventually speeds approaching 150 “as 4G LTE network and devices evolve” The fine print , - actually it is in normal print in this case – states average speeds are in the 12-25 Mbps range.
2. Rogers – currently up to 75Mbps and later in the year approaching 100Mbps. The site notes that “Today, devices are capable of downloading up to 75 Mbps and Rogers LTE customers are experiencing typical download speeds ranging from 12 Mbps to 25 Mbps.”,
3. Tbaytel – No information about LTE on the website.
   

Information about LTE’s actual users’ rates tend to be anecdotal. While I was able to find a few examples of users claiming speeds in excess of 40 Mbps, this appears to be the exception. The majority of users reported download speeds in the range from 8 to 30 Mbps with speeds in the low 20 Mbps being very common. This seemed similar across both LTE networks. Upload speeds tend to be about one third of the download speeds for any given test cycle.

When I extrapolate these results to what we can expect with IMT-Advanced. I draw the following conclusions:

1. It is unlikely that real world IMT-Advanced speeds will approach the theoretical rates
2. Average network download speeds will increase to a level that will provide near real time transfer of movie and other large data files
3. Vendors are getting better at advertising speeds that users can expect and are doing so in a more open way. In turn, users are reporting actually receiving these advertised speeds.

This is a summary overview of the Mobile data speeds.

	Theoretical/Advertised Speed	Expected Speed
3G/4G HSPA*	7.2 Mbps (Standard)	3.5 -6 Mbps
	21 Mbps (Premium)	3.5 – 8 Mbps
	42 Mbps (Limited)	7 -24 Mbps
LTE	150 Mbps	12 -25 Mbps
IMT-Advanced	1 Gbps (Static) 100 Mbps (Moving)	Unknown

*Only service available in the Algoma District as of 29 Jan 2012

To find out where the various speeds are available, see the vendor websites for coverage maps: Bell - Rogers - Tbaytel