This version (06 Jan 2021 16:44) was approved by Robin Getz.The Previously approved version (10 Apr 2017 19:21) is available.
How far/fast?
The first two questions asked by many novice users of wireless communications are always:
- How fast does it go?
- How far does it cover?
The answers are not practical to answer for a device like the ADALM-PLUTO, or any other SDR since you can gain distance by giving up datarate, gain data rate by increasing bandwidth, gain data rate by changing modulation scheme. The performance (how far/fast) of the system will depend heavily on everything from the choice of carrier frequency, modulation type, bandwidth, antennas, local environment (topography, vegetation, weather), just to name a few.
Data Links vs Radios
One of the first things to understand from a novice standpoint is the difference between a data link and a radio.
At the top level, a data link connects one location to another for the purpose of transmitting and receiving digital information. In most instances, we have a transmitter and a receiver and the channel. These are governed by a link protocol enabling digital data to be transferred from a data source (transmitter) to a data sink (receiver). The data link specifies everything that both the transmitter and a receiver need to know to communicate effectively. This includes such things as:
- occupied bandwidth
- center frequency
- modulation types supported
- negotiation of modulation types (if supported)
- MAC protocol (multi-master, master-slave, CSMA, etc)
When asking questions about how far, how fast, bit error rate - these are characteristics of a data link, not a radio.
Since the ADALM-PLUTO is a radio, not a datalink, it is difficult to answer those questions.
For analyzing data links, there is a great article at AFAR Communications which reviews these sorts of things.
university/tools/pluto/users/far_fast.txt · Last modified: 10 Aug 2017 02:41 by Abhinav Uppal