Machine type communication (MTC) has been discussed in the 3GPP standard. For MTC applications of certain types, a terminal with ultra-low power consumption and a corresponding communication method are crucial.
In the current society, there is such a need, for example, for a children mobile phone, to inquire the location of a child. However, in case of emergency, the mobile phone may not always be recharged in time after running out of battery. Therefore, in this case a terminal with ultra-low power consumption is needed to periodically notify (or to be triggered to notify) a wireless network and it can work for a very long time to transfer key information, such as a specific location or “I am alive”. By using such a communication method, the wireless network can track the status of the terminal for a long time.
The challenge to MTC terminals of this type is to have a battery life that is several years long. For reference, the longest standby time of an existing terminal is just several months.
Power consumption of a terminal may be divided into several parts:
power consumption of the terminal in an idle state, which is determined by a power saving technology of the terminal, for example, design of a chip with an ultra-low leakage current;
power consumption of the terminal to synchronize and obtain information broadcast by a cell;
power consumption of the terminal to intercept common control channel information (for example, paging information or scheduling information);
power consumption of the terminal to transmit uplink data; and
power consumption of the terminal to receive downlink data.
FIG. 1A and FIG. 1B depict a process of GPRS (General Packet Radio Service) data transmission. As can be seen from FIG. 1A and FIG. 1B. This process includes transmission of lots of uplink signaling data and reception of lots of downlink signaling data. If an existing communication method is used, the longest battery life of the MTC terminal will not be more than half a year, and it is very difficult to further reduce power consumption of the MTC terminal.