Why the trend to have SSID prefix start as "Direct-xx"?

Question

I've noticed this trend that WIFI SSIDs now start with a prefix of "Direct-xx" (ex: Direct-EK-Bravia).

I've been unable to find anything that points to a new standard or requirement? Is this just say one company (say Intel) requiring all wifi endpoints to have a non changing prefix out of the 32 allowed characters?

Solution

It's because those devices are setup for WiFi-Direct.

From a protocol point of view a Wi-Fi direct connection is established using already existing mechanisms in a number of steps:

In a first step, the two devices that are to connect directly have to find each other. This is done by sending standard Wi-Fi probe request and response frames that include the Wi-Fi direct specific generic SSID “DIRECT-” and further Wi-Fi direct capability information. A device answering with a probe response frame uses the same SSID and includes vendor specific tagged information elements to also identify itself as a Wi-Fi direct device and gives further information such as its direct mode capabilities, device type and a name in readable format that can be presented to the user.

Source

The GO [Group Owner] starts to operate in Access Point mode, sending beacons with the negotiated SSID and a group formation bit set to 1, because the group formation has not yet been completed. The SSID is standardized to be "DIRECT-xy..." with xy being random characters/numbers and any postfix.

Source

Comments

[TJJ]

It seems to be related to WiFi-networks from Sony Bravia TVs. But in general, if repeating strings in WiFi networks occur, this would typically linked to a common ISP in that area that hands out WiFi-Hotspots with their service.

[Jakub]

no it isn't related to Sony, I've seen GM 4G hotspots start with this (latest model year) also printers, etc; Please provide reference if you are providing an answer.

[TJJ]

Well, I wrote "seems". Because that's what my Google search turned up. E.g. youtube.com/watch?v=xMDgKUYAho0 "Direct" probably means something like "WiFi-Direct", where you connect directly to the device instead of having an accesspoint in the middle. But there is no enforcement of a specific SSID by a specific manufacturer.