nn::cec::CTR Namespace

Namespace for the CEC library.
(This namespace can also be written without the ::CTR portion.)

CTR StreetPass is an improved and easier-to-use iteration of a similar Nintendo DS feature called Chance Encounter Communication (CEC).
Because the system performs the communication in the background, sending and receiving data can be performed simply by preparing the send data, regardless of the application running or its status. However, because an application's original communication processes cannot be implemented, there is a chance that implementation of send/receive methods that require special conditions may not be possible.

StreetPass communication is enabled by creating a StreetPass box in the area prepared by the system and registering StreetPass data as the message to send in it. This allows the system to automatically send/receive StreetPass data with communication partners.
There are 12 StreetPass boxes available. In principle, one application can exclusively own one StreetPass box. If all StreetPass boxes are already in use, no new StreetPass boxes can be created until the user deletes unnecessary StreetPass settings on the StreetPass management screen in the system settings.
The StreetPass box contains a send box and a receive box. Each is allocated as a region to register StreetPass data to be sent and as a region to store received StreetPass data, respectively.
When two units that can perform StreetPass near each other and discover each other, the StreetPass box in the other unit's system region is scanned first. If there is a StreetPass box created with the same application (title ID) in the other's unit, communication begins only for the portion required for StreetPass send and receive data. When StreetPass data from several StreetPass boxes is to be sent, the data is sent from the smallest in size. But the communication partners may not remain in an area where they communicate long enough for all of the StreetPass send and receive data to be completed. When they are in the communication area for a short time, it is possible only the smallest data sent initially may be successfully communicated to the first person. For this reason, it is effective to keep the StreetPass data size as small as possible to increase the communication success rate. In addition, if they are not grouped, only one block of StreetPass data can be sent from one StreetPass box.
Depending on the settings, StreetPass data that can only be received can be saved, but be aware that StreetPass will not occur between receive-only data units. This situation also applies to StreetPass data that can only be sent. Specifically, if the first registered data is fixed as receiving or sending only, StreetPass data will never occur, no matter how much time passes.
StreetPass with the same partner will not occur again until an average of 4 hours or a maximum of 8 hours elapses.

2010/08/16

Initial version.