RE: [PATCH v2 5/7] text-telephony: add documentation
Hi,
On 23 Nov 2010, Lucas De Marchi wrote:
+Interface org.ofono.TextTelephony
[...]
+Properties boolean Powered [readwrite]
+
+ This property will enable or disable the text
+ telephony feature in the modem.
+
+ Text telephony (TTY), also known as TDD, is a feature
+ present in some modems that allow them to be used by
+ hearing impaired people.
just to clarify, I guess this covers all aspects of TTY
support handled by the modem?
E.g. for modems, TTY/CTM support can mean:
- signaling TTY/CTM support as a capability (e.g. in Bearer Capability
of 24.008 at the start of calls) ->all modems that support TTY
do this
- above plus: performing CTM coding on modem ->some modems
- above plus: handling audio input/output ->some modems
So depending on the modem, enabling TTY with this new oFono
interface enables all of the above (those the apply), right?
This makes sense as AFAIK there is no need to control the different
aspects separately (and is analogous to handling voice calls
in general with oFono), but just making sure I understand
the semantics correctly.
If in the future ofono clients need more information about the speech
data path processing (w.r.t. TTY), that can be then added to
org.ofono.AudioSettings interface (e.g. whether modem does
CTM coding, whether it supports HCO/VCO (does voice go through
at all when TTY mode is enabled). But until we have a modem (and
use case) that needs this, it's too early to add these. E.g. Nokia
N900 does not support TTY, but if the support was added, in theory
it could technically do CTM coding both on modem and/or on Linux
side.
br,
--
Kai Vehmanen