Chief Airwave weaknesses
1) Vehicle mounted repeaters cannot co-operate. Two vehicles (police, fire, ambulance) at one scene, only one can operate.
2) Max capacity of a mast is 16 callers. Take police, add fire and ambulance and highways at a major incident and share it out.
3) The handset emergency button can take many minutes in the "queue" to have any effect, so not the immediate assistance claimed.
4) Encoding between towns is reduced, so signal jamming possibility drops to a permutation of 8 (compare "number of rings in your bicycle combination lock")
4) No signal fade as with VHF; it's all or nothing. If no weak signal, no awareness that anything is lost.
5) Data capacity is a feature of bandwidth. TETRA is inherently low, hence police resort to commercial phone network, without encryption, but depend on public capacity. New year's eve must be a very good time to call up for data!!
6) Masts are very public. If a terrorist cell can learn to fly a jumbo, they can spot a TETRA mast! portable devices are available that emit electromagnetic pulses to knock a mast out. Actually a single pin in a cable would, I guess, do the same and be very hard to find. Equipment required very sophisticated: a ladder and a pin.
7) You may recall the Manchester fire in a BT tunnel that wiped out phones and Internet links. TETRA is linked up by phone lines, and was temporarily knocked out regionally by the fire. Got priority of course. But what if the fire WAS the emergency, and the fire service and uncle Tom Cobbly and all were relying on Airwave to sort it out? What a great target, to simultaneously wipe the emergency infrastructure AND distract attention from a real target...
8) Viruses? Unlikely in TETRA because it isn't public access, but the more supplementary commercial kit is used, the more that is likely to suffer as it does for everyone else.
Oh, and if you're concerned:
9) All the police encryption keys are kept in the US, passed to Menwith Hill etc. and the US intelligence is listening to everything anyway. MI5 can't. Are the US security forces free from corruption? No chance that deals are being done? No inside jobs, like maybe for 9/11? Hmmm. You might think that, I couldn't possibly comment.
Andy
From Mast Network
2) Max capacity of a mast is 16 callers. Take police, add fire and ambulance and highways at a major incident and share it out.
3) The handset emergency button can take many minutes in the "queue" to have any effect, so not the immediate assistance claimed.
4) Encoding between towns is reduced, so signal jamming possibility drops to a permutation of 8 (compare "number of rings in your bicycle combination lock")
4) No signal fade as with VHF; it's all or nothing. If no weak signal, no awareness that anything is lost.
5) Data capacity is a feature of bandwidth. TETRA is inherently low, hence police resort to commercial phone network, without encryption, but depend on public capacity. New year's eve must be a very good time to call up for data!!
6) Masts are very public. If a terrorist cell can learn to fly a jumbo, they can spot a TETRA mast! portable devices are available that emit electromagnetic pulses to knock a mast out. Actually a single pin in a cable would, I guess, do the same and be very hard to find. Equipment required very sophisticated: a ladder and a pin.
7) You may recall the Manchester fire in a BT tunnel that wiped out phones and Internet links. TETRA is linked up by phone lines, and was temporarily knocked out regionally by the fire. Got priority of course. But what if the fire WAS the emergency, and the fire service and uncle Tom Cobbly and all were relying on Airwave to sort it out? What a great target, to simultaneously wipe the emergency infrastructure AND distract attention from a real target...
8) Viruses? Unlikely in TETRA because it isn't public access, but the more supplementary commercial kit is used, the more that is likely to suffer as it does for everyone else.
Oh, and if you're concerned:
9) All the police encryption keys are kept in the US, passed to Menwith Hill etc. and the US intelligence is listening to everything anyway. MI5 can't. Are the US security forces free from corruption? No chance that deals are being done? No inside jobs, like maybe for 9/11? Hmmm. You might think that, I couldn't possibly comment.
Andy
From Mast Network
Starmail - 12. Mär, 12:01
