Why M2M devices don’t roamJuly 21, 2012
Using cellphones has made us very familiar with the concept of home networks and roaming. The home network is the one owned by the operator with who we have a subscription. If we join a different network we are considered to be roaming and often pay a much higher tariff for the privilege. But such a concept need not and indeed should not apply to machine communications.
Take the example of a Japanese car manufacturer such as Honda. They might embed Weightless M2M chips within the engine management system of cars that they are building. These cars will leave Japan and be delivered all around the world. Even once delivered they may move from country to country, both when owners travel and when the car is sold on. Ideally they should locate a Weightless network wherever they happen to be and communicate seamlessly. The concept of a home network and roaming makes little sense in this case. The difference occurs because the billing relationship is with Honda which is a multi-national company and not with an individual spending most of their time in one country.
Of course there will be national networks and Honda will need to pay these for the traffic carried. Weightless has the concept of a service provider who has an agreement with multiple operators around the world and offers Honda and others a service across all these networks. The service provider becomes the “home” for the device. The Weightless devices – cars in this case – always connect to this service provider through partner national networks. In this case there is no roaming, just the network the device happens to be connected to. There are certain implications of this arrangement – for example security keys cannot be stored in the “home network” because there is no such thing. Instead they are stored at the service provider level in a secure manner that allows companies to change service providers should they wish.
This is yet another example of how a network designed for people is inappropriate for machines. This has been recognised to some degree by cellular operators, some of whom are working with Jasper Wireless to try to establish an approach that enables machine roaming. But, as we have observed, machines do not roam and so this approach will always be second best to a custom-designed network.This entry was posted in Uncategorized. Bookmark the permalink. ← Government investment in infrastructure The PCAST report →