Radio Data Link Access Procedure (RD-LAP)

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Radio Data Link Access Procedure (RD-LAP)
RD-LAP image.jpg
Frequencies 150 MHzMegaHertz (MHz) 10^6 Hz150,000,000 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).
150,000 kHzKiloHertz (kHz) 10^3 Hz
,850 MHzMegaHertz (MHz) 10^6 Hz850,000,000 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).
850,000 kHzKiloHertz (kHz) 10^3 Hz
150,000 kHzKiloHertz (kHz) 10^3 Hz
150 MHzMegaHertz (MHz) 10^6 Hz
850,000 kHzKiloHertz (kHz) 10^3 Hz
850 MHzMegaHertz (MHz) 10^6 Hz
Frequency Range 150 MHzMegaHertz (MHz) 10^6 Hz150,000,000 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).
150,000 kHzKiloHertz (kHz) 10^3 Hz
- 850 MHzMegaHertz (MHz) 10^6 Hz850,000,000 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).
850,000 kHzKiloHertz (kHz) 10^3 Hz
Mode NFMNarrowband Frequency Modulation
Modulation 4FSK4-Level Frequency Shift Keying
ACFAutoCorrelation Function
Bandwidth 12500 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).12.5 kHzKiloHertz (kHz) 10^3 Hz
0.0125 MHzMegaHertz (MHz) 10^6 Hz
,25000 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).25 kHzKiloHertz (kHz) 10^3 Hz
0.025 MHzMegaHertz (MHz) 10^6 Hz
12.5 kHzKiloHertz (kHz) 10^3 Hz
0.0125 MHzMegaHertz (MHz) 10^6 Hz
25 kHzKiloHertz (kHz) 10^3 Hz
0.025 MHzMegaHertz (MHz) 10^6 Hz
Location Worldwide
Short Description Motorola's Radio Data Link Access Procedure (RD-LAP) is a 1G protocol that was used in ARDIS and DataTAC Networks, and is still used in some MDTMobile Data Terminal, A mobile data terminal (MDT) is a computerized device used in public transit vehicles, taxicabs, commercial trucking fleets, military logistics, and emergency vehicles, such as police cars, to communicate with a central dispatch office.'s, as well as gas companies, police departments, fire departments, financial companies, etc.
I/Q Raw Recording Download file
Audio Sample

Motorola's Radio Data Link Access Procedure (RD-LAP) is a 1G protocol that was used in ARDIS/Motient and DataTAC Networks, and is still used in some MDTMobile Data Terminal, A mobile data terminal (MDT) is a computerized device used in public transit vehicles, taxicabs, commercial trucking fleets, military logistics, and emergency vehicles, such as police cars, to communicate with a central dispatch office.'s, as well as gas companies, police departments, fire departments, financial companies, etc. Its use has been on the decline as faster cellular networks are adopted and P25 used for public safety.

This format was developed from MDT4800 (4.8kbps). RD-LAP has faster data rates (9.6kbps/19.2kbps). The majority of deployments used the 19.2kbps mode.

Characteristics[edit]

When idling, the 9.6 kbpsKilobits per second (kbps) mode has an ACFAutoCorrelation Function of ~25 msmilliseconds (.001 of a second) (40sym/s), where the 19.2 kbpsKilobits per second (kbps) mode has an ACFAutoCorrelation Function of ~12.5 msmilliseconds (.001 of a second) (80sym/s). RD-LAP employs 4FSK4-Level Frequency Shift Keying modulation with frequency deviations at -3600 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz)., -1200 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz)., +1200 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz)., and +3600 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz)..

Maximum message size is 2,048 bytes. Max OTA size is 512. 4FSK4-Level Frequency Shift Keying with SRRC filtering rO = 0.2. 9.6 kbpsKilobits per second (kbps) in 12.5 kHzKiloHertz (kHz) 10^3 Hz channels; 19.2 kbpsKilobits per second (kbps) in 25 kHzKiloHertz (kHz) 10^3 Hz channels

Trellis coded modulation, r = 3/4.

32-bit interleaving protects 1.7 msmilliseconds (.001 of a second) Cascaded CRCs with a final 32-bit CRC.

Samples[edit]

9.6 Kbps[edit]


19.2 Kbps[edit]




Denver Taxi MDTMobile Data Terminal, A mobile data terminal (MDT) is a computerized device used in public transit vehicles, taxicabs, commercial trucking fleets, military logistics, and emergency vehicles, such as police cars, to communicate with a central dispatch office. at 152 MHzMegaHertz (MHz) 10^6 Hz:

Unknown taxi MDTMobile Data Terminal, A mobile data terminal (MDT) is a computerized device used in public transit vehicles, taxicabs, commercial trucking fleets, military logistics, and emergency vehicles, such as police cars, to communicate with a central dispatch office.:

New York City RD-LAP at 855.211 Mhz:


New York Police Department RD-LAP w/with Morse Code callsign WIM662 at 483.662 MHzMegaHertz (MHz) 10^6 Hz

Barnwell County, South Carolina at 854.862 MHzMegaHertz (MHz) 10^6 Hz

Additional Links[edit]

Additional images[edit]