I’d like to get the terminology correct when differentiating between a P25 simulcast system’s “sites” and what to call the various transmit and/or receive locations within each site. I’ve been referring to these various locations using the word “location”. But I believe I’ve seen the term “sub sites” used also. Previously, I thought the term “site” referred to the only transmit/receive geographical location serving a specific area. But recently I’ve come to learn a “site” can be a collection of more than one transmit/receive towers within a single site’s area. So, what to call these towers? Sub sites? Nodes?
Simulcast Termonology
- Thread starter n1chu
- Start date
Also some users confuse when a Trunking System Talkgroup sets up a VHF link so they can still page members with pagers it is referred to as Simulcast and people think the entire system is Simulcast which it is not. We need some term to use to separate the 2.
The correct term for the multiple geographically separate TX/RX sites that together make up a simulcast cell is subsite. The whole of the simulcast cell can be referred to as either a cell or a site, as each subsite broadcasts the exact same info/voice/data simultaneously. There is no uniqueness to each subsite on the RF side; they purposely appear as a single RF site to subscribers.
nd5y
Member
Simulcast means the same content is transmitted on the same frequency from different locations.
Multicast means the same content is transmitted on different frequencies from the same or different locations.
This is what is used commonly. People get confused all the time even on the StarCom 21 system. Some are multicast and some are actually simulcast. Often the database has those simulcast areas listed, which helps people decide what device they might need to better receive them at least in some areas better.
Would that be considered a “patch”?
Ok. Now I have what I need to accurately express myself and (hopefully) not confuse the issue. But I’d sure appreciate it if the term “subsite” was removed all-together. It just makes better sense to me to describe a simulcast system as composed of various cells, or coverage areas. And those cells are comprised of sites, namely the exact geographical location of a transmitting/receive tower. Then again, we have “cell sites”, commonly used in cellular lingo. But my main objective was to obtain the correct terminology, I can now follow a post on the subject and refer to the differences correctly.
Thank you for clearing my confusion.
I'm not sure what the issue is. The term subsite has been used for decades. A simulcast site is comprised of multiple subsites. It really doesn't get any simpler than that, so no need to overcomplicate things.
The very definition of the word subsite is "a site that is part of a larger site"
PS - Technically, it's not the system itself that is simulcast, but rather the site(s) that are part of the overall system which are either simulcast or standalone (or a mix of both). Semantics, perhaps, as a system comprised exclusively of one or more simulcast cells with no standalone sites would effectively be a "simulcast system", but for the sake of better understanding how these trunked systems work and the related terminology...there you have it.
The very definition of the word subsite is "a site that is part of a larger site"
PS - Technically, it's not the system itself that is simulcast, but rather the site(s) that are part of the overall system which are either simulcast or standalone (or a mix of both). Semantics, perhaps, as a system comprised exclusively of one or more simulcast cells with no standalone sites would effectively be a "simulcast system", but for the sake of better understanding how these trunked systems work and the related terminology...there you have it.
There is no issue, never was. I merely wanted to know what the most accepted form was.
That is correct. You raise a good question. It’s a personal preference and raises no issue as long as I am willing to conform to it, which I am. But it does make me wonder why RR decided to use the term “site” when cellular telephone uses “cell”, and has since its inception. I realize either term, with their broad definitions, can be used interchangeably.
These are industry terms, not RadioReference concoctions. The terms "site", "subsite", "simulcast cell", etc. are well established within the industry, and can routinely be found in APCO and TIA-102 documentation/specs, as well as common usage by every manufacturer such as MSI, L3Harris, Tait, etc.
Here is just one example straight out of the latest ASTRO 25 glossary. And yes, there's another term to throw into the mix...Simulcast Remote Site. How about another one? ASR or ASTRO 25 Site Repeater, MSI's term for a standalone (non-simulcast) P25 site (which, contrary to the name, does not refer to a single repeater at a site, but rather to the whole site itself, which may be equipped many repeaters).
QPLou5645187
Member
Really good conversation here! I had no idea of what trunking, simulcast, or multicast even was. When I see things like this, I research them and learn what they are. Thank You for the education!
There is a lot of confusion on this. At times it annoys me. The National Park Service has developed a number of systems in some parks where all the repeater sites in the park multicast the same signal on every repeater in the system with each repeater on its own frequency pair. This enables personnel in all parts of the park, regardless of topography, to hear whatever is being transmitted, park wide. Each repeater is linked via UHF (406-420 MHz) with all the other repeaters. The same is done on large fires for the command repeater network. In too many discussions people call this simulcast and that is just plain wrong. The commercial broadcast industry is responsible for much of the confusion. They will sometimes state that the audio on a TV broadcast will be simulcast on an AM radio station. This is common for sporting events. This, when in fact, they are multicasting on an AM radio station and a TV station.
All good info. Keep it coming.
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