ScanRiverside.com

coruptr wrote:

cvrules90 wrote:I know that Channel 7 is digital and encrypted.

Correct, some transmissions are encrypted using ADP software encryption. When RPD transitions to P25 they will be using DES-OFB. The current rumor is this will occur EOQ1. I've also heard rumors they are switching to PSEC. So, we're just going to have to wait and see.

RPD is going to P25? I didn't know that. LAPD copycats I guess. As for switching to PSEC, that wouldn't surprise me, it seems that everybody's trying to make a system like the OC system.

coruptr wrote:

cvrules90 wrote:I know that Channel 7 is digital and encrypted.

Correct, some transmissions are encrypted using ADP software encryption. When RPD transitions fully to P25 they will be using DES-OFB (not confirmed - rumor only) on all channels. One of the current rumors is this will occur EOQ1. I've also heard another rumor they will be switching to PSEC. So, we're just going to have to wait and see.

Coruptr, how did you determine they are using ADP encryption?

cvrules90 wrote:

coruptr wrote:

cvrules90 wrote:I know that Channel 7 is digital and encrypted.

Correct, some transmissions are encrypted using ADP software encryption. When RPD transitions to P25 they will be using DES-OFB. The current rumor is this will occur EOQ1. I've also heard rumors they are switching to PSEC. So, we're just going to have to wait and see.

RPD is going to P25? I didn't know that. LAPD copycats I guess. As for switching to PSEC, that wouldn't surprise me, it seems that everybody's trying to make a system like the OC system.

There are a few good reasons an agency may switch to P25 instead of staying analog. P25 (or any digital format for that matter) allows the best enviornment for the use of encryption. Older analog encryption schemes like DVP occupy 25 khz of bandwidth which is no longer legal on 450-470 mhz however, some cheap voice inversion SCRAMBLING schemes will work at 12.5 khz. Additionally, P25 allows for better access control and identification of subscribers and overcomes the higher noise to signal levels that plague narrowband (12.5 khz spaced channels at 2.5 khz deviation) analog radio. P25 essentially allows for cleaner recovered audio in fringe areas but like any digital mode, drops off sharply when it does drop off. Also, any equipment that is purchased on Federal or State grants must be P25 compliant, so a lot of the newer equipment is technically capable of running P25 if the operator chooses to run it in that mode.

I didn't know that. Thanks for the info.

Refarming the spectrum to more tightly spaced channels for better spectral efficency is what drove manufacturers to go away form analog to digital. At under 10-11 Khz or so, analog performance is marginal at best and getting good analog performance (audio levels and good adjacent channel protection characteristics) at 6.25 khz (the future goal of LMR refarming above 50 mhz) is pretty much impossible, hence the new digital formats.

N6AJB wrote:

coruptr wrote:

cvrules90 wrote:I know that Channel 7 is digital and encrypted.

Correct, some transmissions are encrypted using ADP software encryption. When RPD transitions fully to P25 they will be using DES-OFB (not confirmed - rumor only) on all channels. One of the current rumors is this will occur EOQ1. I've also heard another rumor they will be switching to PSEC. So, we're just going to have to wait and see.

Coruptr, how did you determine they are using ADP encryption?

I was informed by a friend who works for the city. The feature was added to the flashcode as a purchase incentive during the transition from Saber I's to the XTS5k's.

Interesting. I know a lot of the newest radios they have been purchasing are the Harris Unity multi band units (which don't support ADP, but do support AES-256 and DES-OFB) so it would be surprising to me if they were using the Motorola proprietary ADP.

N6AJB wrote:Interesting. I know a lot of the newest radios they have been purchasing are the Harris Unity multi band units (which don't support ADP, but do support AES-256 and DES-OFB) so it would be surprising to me if they were using the Motorola proprietary ADP.

I think OC has DES-OPB in their car and portable radios.

N6AJB wrote:Interesting. I know a lot of the newest radios they have been purchasing are the Harris Unity multi band units (which don't support ADP, but do support AES-256 and DES-OFB) so it would be surprising to me if they were using the Motorola proprietary ADP.

It appears my information is a bit more dated than I thought. I wasn't aware RPD had purchased XG-100P's and I'm guessing mobiles too. With this in mind I wonder what the plausibility is for RPD to switch to PSEC. Hmmm?!?!

I think the goal is PSEC CAPABLE radios as mutual aid users, or at the bare minumum 800 mhz conventional capability for interop. It is still unknown if Riverside will subscribe to PSEC or upgrade the existing (aging) system.