Wednesday, June 28, 2006

Dean Bubley: Redefining seamlessness

Dean Bubley posts his thoughts on the term "seamless" at the Disruptive Wireless blog. He thinks it's "a nonsense term - at best an irrelevance, and at worst a dangerous distraction." Bubley notes:

Up until now, "seamless" has tended to be used mostly by people talking about handing off voice calls from cellular to WiFi networks, using dual-mode phones. It's one of the features of UMA (which was designed around facilitating it) and it is often emulated/hyped/exaggerated about the various SIP and IMS/VCC based alternatives.

The idea is that the end-user should remain blissfully unaware of what the technology is connecting him or her to the network, even if that connection changes "seamlessly" mid-call.
Bubley thinks "Seamless handover is a nice-to-have - but only if it doesn't introduce problems elsewhere." He writes:
This all fits in with one of the biggest fallacies with IMS - that applications or services should be "bearer agnostic" - ie work the same, irrespective of whether they're connected over 2G, 3G, WiFi, WiMAX, ADSL or a piece of wet string. And that they should be able to switch over "in mid-flight".

This ignores the fact that at the "seam" lots of things change. Bandwidth, latency, price, maybe ownership, control, security, context and lots of other things. While the user should (in some cases like an ongoing voice call) have minimal interaction, the device itself and its resident applications need to be fully bearer-aware to enable a good user experience, especially for data applications. Moving from a low-latency to high-latency connection has a huge impact on software that has complex "hand-shaking" procedures, for example. And moving from an unlimited-data environment (eg home or office WiFi) to one that is tariffed per-MB clearly needs intervention. If I have anti-virus software, for example, I don't want it downloading 5MB of stuff unannounced, especially if I'm roaming. And I want the music application on the device to recognise I'm at home on WiFi, and default to getting MP3s from my PC hard drive, rather than defaulting to the operator music portal.
Bubley concludes with some observations he made at a conference where both BT and DT essentially started to redefine the term "seamless". He states:
Both speakers said that "seamless handover between bearers" was not essential - but that access to certain functions like address book or voicemail was. I agree with this - and if "seamless" is to be more generally used as a marketing-friendly way of saying "multi-access", I may reconsider my views about the credibility of its proponents.