Patent ID: 8712483

Claim:
A radio system comprising: a slave comprising a short-range transmitter and a wake-up radio receiver, wherein the slave is configured to have a sniff sub-rating with a master, the master being configured to wake up the slave via the wake-up radio receiver, wherein the master and slave define a sniff period (T sniff ) comprising a period between successive sniff event times, wherein the slave is scheduled to wake-up once every predetermined number of sniff periods, the predetermined number being greater than one; wherein when the master initiates communication with the slave prior to the slave's scheduled wake-up time by transmitting a wakeup message to the slave, a latency associated with the slave's response to the wakeup message does not exceed the sniff period (T sniff ), and wherein when the slave initiates communication with the master prior to the slave's scheduled wake-up time, a latency associated with the slave's communication with the master does not exceed the sniff period (T sniff ).