Monday 30 January 2012

Dropped Mobile Calls

“Jp” sent me the following comment:

“I have been having a problem just a week before Christmas my bell iPhone 3GS is constantly searching or dropping signal. I have called numerous times and was told to change my SIM card which did nothing. I thought my phone was to blame and a few other people I work with say they are having the same problem. One co-worker of mine told me he heard that bell had sold some of their towers to Rogers and that is why we have a weaker signal. Maybe bell is gearing up for 4g in the north so they sold some towers to finance the north project.”

I am not sure I can provide the definitive answer for this particular case but it raised a number of issues so I decided to address it as a separate blog. As a caveat, I do not represent Bell nor do I have any special access to individual call information.

Since the issue involves Bell hardware it is safe to assume the disconnect problems did not occur in the North Sault area.

The obvious solution is to continue to escalate the problem within the Bell customer service system. I know first-hand this can be a frustrating process at times but it does work with enough patience. Be sure to keep a record any exchanges showing date and time, general subject, and employee ID.

It might also be useful  to look at some of the causes for dropped calls.

The most common reasons for dropped call on a Mobile network are network congestion and poor handoff between cells. Vendors do not like to admit this and will try to assign the blame to some element under the user’s control. This is not to say there may well be other hardware or network problems that could cause dropped calls.

As noted in previous blogs, the main cause of network congestion is too many network demands chasing too few network resources. In other words, the number users trying to access a cell outnumbers the capacity of the cell. Each cell has a priority list on how it handles traffic. As congestion begins, the cell gracefully degrades service until it arrives at the ultimate solution which is a dropped call. (Gracefully degrade is “geek speak” for slowing individual data speed down so more people can use the limited bandwidth. This is one reason why some rural users get a better speed during the day and slow down drastically after school and in the evenings. The last data to be dropped is usually voice.)

If a particular locality is identified as a problem area, vendors have a number of options to address the problem. They include, inter alia; add more cell sites to create smaller coverage areas and therefore fewer users per cell; add additional carriers to a cell site which increases the number of calls it can handle; add a separate frequency chain. One or all of these solutions have been used in the Algoma District to varying degrees of success.

All vendors are continuously upgrading and adding to their networks. Unfortunately, vendors worldwide have generally underestimated the growth of Mobile data demands over the last few years and have been playing catch-up to get ahead of the growth curve. This Nielson chart indicates the growth trends by quarters where information is available.


Poor handoff is more likely to occur while the user is on the move. There have been some discussions in the cyber world about carriers deliberately dropping roaming calls but I have not seen or heard any conclusion of this accusation.

As to Bell selling towers to Rogers. I doubt there is much validity to this rumour. There may be confusion because federal regulations encourage the sharing of tower amongst all the carriers and there are numerous sites in the north where Bell and Rogers hardware is on Rogers’ towers and vice versa. Some sites are owned by a third party such as the Bellevue site owned by MTS Allstream.

Bell has more than enough financial resources to fund the North Sault expansion without selling assets in other locations. I doubt they would rob Peter to pay Paul, especially if it involved their principal competition.


  1. Finally someone who understands the unexpected growth isn't just an issue for one carrier.

    Canadian carriers Rogers, Wind, Mobilicity, Bell, Telus, Tbaytel, Bell Aliant, MTS, SaskTel, KMTS, DMTS, Public Mobile and Vidéotron Mobilité are all experiencing congession issues.

    This isn't just a made in Canada problem, providers worldwide are struggling with the demand for bandwidth on their networks. The proliferation of smartphones worldwide is expected to pass 50% in the near future. Less than 2 years ago the number of smartphone users was in the mid-teens.

    Tech companies simply can't meet the demand for their products and services. Ericcson had a heard time filling antenna orders in 2011, leaving carriers waiting between 8 and 10 months for delivery.

    This is just the tip of iceberg as we move away from wired solutions and gravitate toward the adaptation of new wireless technologies. The demand for mobile data is only going to increase in the future.

  2. Thanks. If anyone is interested in a detailed study of Mobile data use and growth, I recommend the CISCO report at