Apparatus for and method of time related communications between multiple devices having different time bases

A method of communicating time related messages between a plurality of devices, said plurality of devices based on different time bases with respect to each other, said method comprising the steps of:

• sending sync events to at least one other device;
• determining a common time based on a local time said sync event was received;
• and
• sending time related messages to other devices, wherein said time related messages comprise time related data expressed in said common time.

An apparatus for communicating time related messages, comprising:

• a plurality of devices having different time bases with respect to each other, each of said devices comprising:
• a timer;
• time conversion means;
• control means coupled to said timer and said time conversion means;
• wherein said control means operative to trigger a sync event whereby interrupts are sent from the timer in one device to the timers in some or all other devices;
• wherein said timers operative to register their respective local times upon receipt of said interrupts;
• wherein said time conversion means on each device is operative to generate and maintain a common time based on respective registered local times;
• and
• means for sending time related messages from one device to another, wherein said time related message comprises time related data expressed in said common time.

A method of sharing a common time base among a plurality of devices, each device comprising a timer based on a different time base, said method comprising the steps of:

• sending sync event interrupts from the timer in one of said devices to the timers in one or more other devices;
• all timers registering their respective local times upon receipt of a sync event interrupt;
• and
• converting, at each device, respective local time to a common time based on said registered local time.

A multi-mode cellular handset for use in a cellular communications network, comprising:

• a plurality of modules, each module comprising a timer and time conversion means, each module adapted to transmit and receive a different radio access technology (RAT) signal;
• inter-module message means coupled to said plurality of modules, said inter-module message means operative to:
• send sync event interrupts from the timer in one of said RAT modules to the timers in one or more other RAT modules;
• register a respective local time in each RAT module upon receipt of a sync event interrupt;
• convert, in each RAT module, respective local time to a common time based on said registered local time;
• and
• send time related messages comprising time related data expressed in said common time from one module to another.

A computer program product characterized by that upon loading it into computer memory a process for communicating time related messages between a plurality of devices based on different time bases is executed, said computer program product comprising:

• a computer useable medium having computer readable program code means embodied in said medium for sharing a common time base among a plurality of devices, each device comprising a timer based on a different time base with respect to each other, said computer program product comprising:
• computer readable program code means for sending sync event interrupts from the timer in one device to the timers in one or more other devices;
• computer readable program code means for registering the respective local times of each timer upon receipt of a sync event interrupt;
• computer readable program code means for converting, at each device, respective local time to a common time based on said registered local time;
• and
• computer readable program code means for sending time related messages comprising time related data expressed in said common time between said plurality of devices.