Brief Introduction to China Mobile WMMP 'Internet of Things Protocol

During this period of time, we have been implementing the China Mobile WMMP Internet Protocol. Now we will briefly summarize this protocol.

This Protocol is mainly used for M2M platform to remotely manage M2M terminals through GPRS network or SMS, including assigning terminal serial numbers and collecting terminal configuration information,

Configure terminal parameters,

Software downloads and updates.

1. Assign the terminal serial number. If no pre-fabricated serial number is available after the terminal is released, register the serial number for the first time when M2M is used.

Key, the password for upstream and downstream communication. If the serial number is pre-fabricated on the terminal, the basic key and the upstream and downstream passwords are used, connect to the M2M platform after power-on.

2. log in. The terminal can log on to the M2M platform after having the serial number, basic key, and upstream/downstream password. After the M2M terminal logs on to the M2M platform, the M2M platform

You can manage the terminal. After the login fails, try several logins. If you still cannot log on, stop logging on. The M2M terminal enters the alarm form.

Wait for the M2M platform to remotely control SMS messages or reset the local device.

The message data of the Protocol does not use the popular XML format, such as OMA-DM, but adopts the traditional format: Header + Body.

The Header is a fixed length of 28 bytes. The maximum length of a message is 64 KB. The Body consists of 0 or more TLVs and 20 bytes of MD5 Digest. TLV (TAG + LENGTH + VALUE) is a formatted data block definition. TAG describes the meaning of VALUE, and LENGTH indicates the actual LENGTH of VALUE.

Compared to the OMA-DM protocol, this protocol is relatively simple to implement. UDP is used in the transmission layer when this protocol is recommended. The packet loss retransmission mechanism is implemented by the Protocol. For each Request, whether initiated on the M2M platform or on the M2M terminal, there must be an ACK in response. The Protocol defines two connection statuses: persistent connection and short connection. Persistent connections are maintained by heartbeat packet requests.