Virtual drive test tool
A channel emulator reads a record of captured radio signal data of a group of cellular base stations in a fielded cellular network from a memory. Based on the record of the captured radio signal data, the channel emulator generates a simulation of a radio environment of the fielded cellular network. In one aspect, the simulation generates a number of live cellular base station signals fewer than the group of cellular base stations in the fielded cellular network. In another aspect, a terrain environment model is applied based on the captured radio signal data.
1. A system, comprising:
a memory storing a record of captured radio signal data of a first plurality of cellular base stations in a fielded cellular network; and
a channel emulator coupled to the memory, the channel emulator comprising one or more processors and accessing instructions executable by the processors including instructions that cause the channel emulator to:
read the record of captured radio signal data of the first plurality of cellular base stations in the fielded cellular network from the memory; and
based on the record of the captured radio signal data of the first plurality of cellular base stations in the fielded cellular network from the memory, generate a simulation of a radio environment of the fielded cellular network, the simulation generating a number of live cellular base station signals fewer than the first plurality of cellular base stations in the fielded cellular network.
2. The system of claim 1 , wherein the first plurality of cellular base stations are captured by a wireless receiver at a particular time of the record.
3. The system of claim 1 , wherein the first plurality of cellular base stations are a total number of base stations captured by a wireless receiver throughout the record.
4. The system of claim 1 , further comprising:
a network emulator generating the number of live cellular base station signals.
5. The system of claim 1 , further comprising:
a second plurality of cellular base stations generating the number of live cellular base station signals.
6. The system of claim 1 , wherein the instructions for the channel emulator cause the simulation to selectively omit particular cellular base stations in the first plurality of cellular base stations.
7. The system of claim 1 , wherein the instructions for the channel emulator cause the simulation to selectively omit particular cellular base stations in the first plurality of cellular base stations, by including a particular cellular base station in the simulation and dropping the particular cellular base station in the simulation responsive to a predetermined drop in total power of the particular cellular base station in the record.
8. The system of claim 1 , wherein the instructions for the channel emulator cause the simulation to selectively omit particular cellular base stations in the first plurality of cellular base stations, by omitting the particular base stations which are not in a strongest set of signals.
9. The system of claim 1 , wherein the instructions for the channel emulator cause the simulation to selectively omit particular cellular base stations in the first plurality of cellular base stations, by omitting the particular base stations which are not in a strongest set of signals, and the strongest set of signals changes with time.
10. The system of claim 1 , wherein the instructions for the channel emulator cause the simulation to compensate for discontinuities between an end and a beginning of the record of radio signal data of the fielded cellular network to allow for looping of the simulation.
11. The system of claim 1 , further comprising:
a wireless receiver coupled to the channel emulator.
12. The system of claim 1 , further comprising:
a wireless receiver coupled to the channel emulator, wherein the wireless receiver is different from a recording device which captured the record of radio signal data of the fielded cellular network.
13. A system, comprising:
a memory storing a record of captured radio signal data of a first plurality of cellular base stations in a fielded cellular network; and
a channel emulator coupled to the memory, the channel emulator comprising one or more processors and accessing instructions executable by the processors including instructions that cause the channel emulator to:
read the record of captured radio signal data of the first plurality of cellular base stations in the fielded cellular network from the memory; and
based on the record of the captured radio signal data of the first plurality of cellular base stations in the fielded cellular network from the memory, apply a terrain environment model for a simulation of a radio environment of the fielded cellular network, the simulation generating a number of live cellular base station signals.
14. The system of claim 13 , wherein the first plurality of cellular base stations are captured by a wireless receiver at a particular time of the record.
15. The system of claim 13 , wherein the first plurality of cellular base stations are a total number of base stations captured by a wireless receiver throughout the record.
16. The system of claim 13 , further comprising:
a network emulator generating the number of live cellular base station signals.
17. The system of claim 13 , further comprising:
a second plurality of cellular base stations generating the number of live cellular base station signals.
18. The system of claim 13 , wherein the terrain environment model compensates for omissions in the record of radio signal data of the fielded cellular network.
19. The system of claim 13 , wherein the terrain environment model compensates for omissions in the record of radio signal data of the fielded cellular network, the omissions including changes in multipath conditions between captured measurements.
20. The system of claim 13 , wherein the terrain environment model causes the simulation to compensate for omissions in the record of radio signal data of the fielded cellular network, the omissions including an amount of line of sight component in a wireless signal.
21. The system of claim 13 , wherein the terrain environment model is determined by combining captured GPS data in the record with geodetic data.
22. The system of claim 13 , wherein the terrain environment model is determined with captured velocity information of a recoding device which captured the record.
23. The system of claim 13 , wherein the terrain environment model estimates a density of cells in the fielded cellular network with captured cell IDs and traveled distance information of the record.
24. The system of claim 13 , wherein the instructions for the channel emulator cause the simulation to switch between multiple terrain environment models during the simulation.
25. The system of claim 13 , wherein the instructions for the channel emulator cause the simulation to switch automatically between multiple terrain environment models during the simulation.
26. The system of claim 13 , wherein the terrain environment model compensates for imperfections in a recording device which captured the record of radio signal data of the fielded cellular network.
27. The system of claim 13 , wherein the instructions for the channel emulator cause the simulation to compensate for discontinuities between an end and a beginning of the record of radio signal data of the fielded cellular network to allow for looping of the simulation.
28. The system of claim 13 , further comprising:
a wireless receiver coupled to the channel emulator.
29. The system of claim 13 , further comprising:
a wireless receiver coupled to the channel emulator, wherein the wireless receiver is different from a recording device which captured the record of radio signal data of the fielded cellular network.