HEM Data Products

Wi-Fi vs. Cellular with In-Vehicle Data Logging

There are many applications for automatic wireless transfer of in-vehicle logger data. These include vehicle/fleet performance, warnings/alert notifications, and tracking. Choosing the right wireless communication is important for cost, update rate, and availability.


Wireless transfer via Wi-Fi can send data either to a local server (intranet) or to a remote server using internet access.. The data logger communicates with a wireless router or other wireless access point to transfer the stored data to its destination.

Wi-Fi requires that the test vehicle or vehicles return to a specific location equipped with a wireless access point, and does so on a sufficiently frequent basis.

Data Frequency
Since the data is logged and then transferred later, stored data files are transferred upon the vehicles return.

Cost to transfer over Wi-Fi is potentially zero if the infrastructure already exists. If not, the costs can consist of a one-time fee for the wireless access point, and additional infrastructure setup. Also, a monthly fee from an internet provider is required to transfer data to a remote server. This is much less expensive than cellular service in multiple vehicles.


Cellular transfer sends data to a remote server using a mobile network operator (MNO) such as Verizon, AT&T or Sprint. A contract with a MNO is required.

Cellular service is available anywhere and anytime that the mobile network operator has coverage.

Data Frequency
Data can be streamed in real-time, or logged and sent at a defined interval or at ignition shut-off.

Cellular cost has a monthly fee based on total kilobytes transferred per month. The monthly fee is not dependent on the transfer rate. The modem price, however, is dependent on the transfer rate.

J1939 Mini Logger™ OBD Mini Logger™ DAWN Telematics™ DAWN™ Software ADAQ Mini™ DAWN Dashboard™