Being a trainer is a nice job. But one shouldn’t use an instant messenger (Skype, Lync, Google Hangout, Jabber, etc.). I always forget to switch it off or change my presence to ‘off-work’ (sometimes does’t help it either). For example it is 9 pm, I’m tired after two weeks of training at a hotel room and watching some movie on my laptop. Then suddenly a window with my IM jumps out and one of my friends (sitting in a different timezone) is asking for some technical advice. He/She sees I’m online and active so it’s not twice polite to ignore the request. Sure, no need to be a trainer, I guess you know it as well.
Presence indication is one of the key attributes of Instant Messaging or Real Time Communication in general. RCS 5.2 is defining the social presence with following attributes:
- Availability, indicates the user‟s (un)willingness to communicate,
- Portrait icon, depicting the user (e.g. a photo or image provided by the contact himself),
- Free text, including textual note and possibility to add emoticons (automatic translation
of some specific characters into smileys),
- Favourite link, to publish hypertext link of personal and/or favourite site,
- Timestamp, date of the last update of the profile, generated automatically,
- Geolocation, depicts the user location.
We shouldn’t limit ourselves only to them. Stop for a while to think about Real Time Communication as about something dedicated to human beings only. For the Machine to Machine communication (M2M/M2X/IoT) it is the presence important maybe even more.
For example a distributor of gas has smart monitoring devices which are all connected to a monitoring station. Moreover some of the devices are interconnected among themselves. Their “social” presence can be related to their readiness, actual throughput, power supply, strength of radio signal, reliability and condition. (However it is true that SIP/IMS/RCS were designed primarily for humans and there are also other ways how to solve presence for M2M.)
UEs and Application Servers rely on the presence information very much. It can be important for both signaling and data. Based on the presence we can choose which device to use, which access method is the best, what timeouts are optimal, which codecs are applicable etc.
Anyway before we’ll dive in the RCS concept of the social presence we should recap the standard mechanisms for SIP defined in the RFC 3903, RFC 2778 and RFC 3856 and the Presence Service for IMS defined in 3GPP 24.141.