The open loop mobile connectivity challenge

The recent additions of stera transit (Visa-SMBC-Nippon Signal-QUADRAC) open loop test systems in Kyushu covering Fukuoka metro, Kuamamoto city transit and JR Kyushu expand the VISA Touch transit boutique deeper into western Japan territory. Open loop based cloud processing advocates like to portray these developments as proof that local processing based FeliCa systems like Suica et al. are expensive bygones due for replacement.

There’s just one little problem that open loop advocates fail to mention: mobile connectivity, aka the Suica app problem, the QR Code payment problem, the Smart Navigo HCE problem, etc. Wide LTE and 5G deployment doesn’t always mean reliable mobile and internet connectivity mobile payment apps depend on, and carrier outages can bring down the transaction processing side of the equation. This was proven, yet again, on July 2 when major carrier KDDI suffered a massive nationwide outage that lasted for 80 hours. Let’s make a quick reference graph for examining local processing vs cloud processing in the mobile era.

Stera is a mobile based payments platform that does away with the NTT Data Cafis dedicated backbone and replaces it with the internet based GMO Payment Gateway. The weak point of course is that since mobile powers the gate reader side, when mobile service goes down, stera gate readers stop working. As everybody found out during the KDDI network meltdown, Mobile Suica kept right on working on the transit gate and the store checkout reader, while mobile app based code payments and point systems all stopped. Some vital services that depended on KDDI connectivity like ATM networks also stopped working.

Cloud based Suica will face these challenges too when it goes online in March 2023. The only difference being how much local processing stays intact and how much system buffering there is (how much it needs to talk with the cloud server to do the job), we shall see. Which brings me to the point I want to make. The media almost always portrays the open loop/cloud vs closed loop/local match as a winner takes all, one size fits all proposition. As the KDDI meltdown proves, this is stupid, and dangerous. Never put all the eggs in one technology basket. I don’t think the risk will go away, not as long as telecommunication company corporate structures don’t foster and promote their engineering talent (the people who actually make things work) deep into the executive decision making forums.

Open loop in Japan is geared for inbound tourists the supplements, but does not replace, the old reliable Transit IC infrastructure which is evolving and reducing costs too. They compliment each other, address different needs and uses. One size doesn’t fit all. If it did, Oyster card would have died years ago.