Error correction for DTMF corruption on uplink
Aspects relate to provision of enterprise call capabilities to mobile devices. For example, a mobile device can indicate, over a data channel, that a PBX is to make a call on its behalf to a called party. The PBX can call back the mobile device, call the called party, and bridge those call legs to establish the call. The mobile device can employ mechanisms that a particular incoming call is made by the PBX. These mechanisms can include using ANI information, sending, and receiving audible verification codes over the voice channel established after answering the incoming call. The verification codes can be selected based different behaviors of the mobile devices.
1. A server system for processing information received over a voice channel during a call, the server system comprising:
a channel interface configurable to communicate over the voice channel with an electronic device;
a non-transitory computer readable medium, coupled to the channel interface, storing sequences descriptive of DTMF tones composing each of a group of feature codes;
a detection module operable to detect tones received on the channel interface;
a translation module configurable for mapping a detected delimiter tone and at least one detected informational tone, when one or more of the at least two informational tones is not detected, into one of the group of feature codes by matching the composition either to the start delimiter and an informational tone that follows or the stop delimiter and a preceding informational tone; and
a compare module operable to compare the detected feature code to one or more feature codes expected to be received.
2. The system of claim 1 , wherein the compare module compares the detected feature code based on the state of the call.
3. The system of claim 1 , wherein the detection module is operative to monitor for information corresponding to at least one feature code available during a call state.
4. The system of claim 2 , wherein the translation module translates the detected delimiter tone and the at least one detected informational tones after the stop delimiter is detected.
5. The system of claim 4 , wherein the detection module resets after the stop delimiter is received.
6. The system of claim 5 , wherein the detection module resets if the stop delimiter is not received with a set time period.
7. The system of claim 1 , wherein the call state proceeds to a successive state if the comparator determines an expected featured codes is present.
8. The system of claim 7 , wherein the call state fails to proceed if the comparator determines one of the expected featured codes is not present.
9. The system of claim 1 , wherein the call state is the state of call functions or call restrictions.
10. The system of claim 9 , wherein the call restrictions comprise blocking international calls.
11. The system of claim 9 , wherein the call functions comprise interactive voice commands.
12. A system for receiving commands during an in-progress call over a voice channel, the commands based on tone description data for a group of feature codes, each feature code of the group respectively defined by a start delimiter tone, a stop delimiter tone, and a pre-determined number of informational tones, the system comprising at least one non-transitory medium storing instructions which, upon execution by at least one processor of the system, cause the system to:
receive voice band signals over the voice channel established for the in-progress voice call between a mobile device and a terminating entity;
identify, in the received voice band signals, a delimiter tone and at least one informational tone but fewer than the pre-determined number of informational tones;
determine a feature code from the group of feature codes based on the received delimiter tone and the received informational tones; and
generate the determined feature code,
wherein the group of feature codes includes a cancel transfer code including a starting delimiter tone comprising a combination of (1) a 1633 Hz tone and (2) two repeating DTMF tones and (3) an ending delimiter tone comprising a combination of (1) a 1633 Hz tone and (2) a tone selected from the set consisting of about 697 Hz, 770 Hz, 852 Hz, and 941 Hz.
13. The system of claim 12 , wherein:
identifying, in the received voice band signals, of the delimiter tone comprises identifying either the starting delimiter tone or the ending delimiter tone;
identifying of the at least one informational tone comprises identifying one of two or more repeating DTMF tones; and
determining comprises matching the sequence of the identified delimiter and the one identified informational tone to corresponding tones of the cancel transfer code.
14. The system of claim 12 , wherein:
identifying, in the received voice band signals, of the delimiter tone comprises identifying the starting delimiter tone and the ending delimiter tone;
identifying of the at least one informational tone comprises identifying only one of two or more available repeating DTMF tones;
determining comprises matching the sequence of the starting delimiter tone, the one informational tone, and the ending delimiter tone to a corresponding feature code.
15. A telephony system for receiving commands during a call over a channel, the commands based on tone description data for at least one feature code, each at least one feature code defined by a start delimiter tone, a stop delimiter tone, and a pre-determined number of at least two informational tones, the system comprising at least one non-transitory medium storing instructions which, upon execution by at least one processor of the system, control the system to:
receive a signal over the channel;
identify, in the received signal, a delimiter tone and at least one informational tone, but fewer than the pre-determined number of informational tones, when one or more of the at least two informational tones is not detected in the received signal; and
determine a feature code based on the identified delimiter tone and the identified at least one informational tone.
16. The system of claim 15 , wherein the determining comprises using a state of the call in determining candidate feature codes for commands useable during that call state.
17. The system of claim 15 , wherein the identifying of the delimiter tone comprises identifying either the start delimiter tone or the stop delimiter tone, and the identifying of the at least one informational tone comprises identifying one of two or more repeating DTMF tones.
18. The system of claim 16 , wherein the state of the call comprises a call transfer.
19. The system of claim 16 , wherein the state of the call comprises that the call has been connected, and the at least one informational tone comprises one tone which is matched to an acknowledgment feature code.
20. The system of claim 18 , wherein the determined feature code is indicative of a cancellation of the call transfer.