Compared to Loran-C signals, eLoran signals are added with a data transmission function. In addition to error correction information, it can transmit time information (universal time coordinated; UTC), almanac information, and so on. It uses the standard time information received from the time synchronization system to generate eLoran pulse signals synchronized with UTC. It also transmits eLoran pulse signals inserted with information of Loran data channel (LDC) received from the transmission station monitoring and control device using a high-power transmitter.

In order to create an LDC message, the 9th Pulse method of the USA and the EuroFix method of the EU are used. These are inserted into the signal with pulse position modulation (PPM). Its role is to convert the correction information received by the eLoran LDC Encoder from the transmission station monitoring and control device into the 9th Pulse and EuroFix methods.

The 9th Pulse LDC inserts an additional pulse following the 8th pulse inside the eLoran pulse group. It creates 32 different time delays with 1 μs as zero time point and transmits 5 bits per GRI.

The 9th pulse LCD message consists of a total of 120 bits, including 4 bits of type information, 41 bits of data, and 75 bits of parity. Accordingly, 24 GRI and 2.4 seconds are required to transmit one message.

Currently, messages that can be broadcast in the 9th Pulse method in the eLoran system include three types in all: positioning correction information (Type 00), almanac information (Type 01), and UTC time information (Type 15).

Eurofix LCDis a method of doing PPM modulation on the 3rd to 8th pulses of the Loran pulse group in unit of 1 μs. The data transmission speed is 7 bits per GRI.

The EuroFix LCD message includes 4 bits for type information, 52 bits for data, 140 bits for parity, and 14 bits for CRC information. The total length of message is 210 bits, and it can transmit 7 bits of information per GRI. Accordingly, it takes 30 GRI and about 3 seconds to send one message.

Currently, messages that can be broadcast through the EuroFix method in the eLoran system include two types in all: UTC time information (Type 06) and positioning correction information (Type 10).