Cellular telephones are enabled by a land-based network of (fixed) antennas. For most of us, these antennas are becoming quite familiar. They're the ones springing up all over, with 3-way antenna arrays, to cover each cell from 3 different towers. There are variations of cell-phone reception according to signal strengths and antenna heights, but the cellular-assignment approach takes care of all that.
cellular communications are fully mobile, though cellular telephones exhibit the obvious "handing-off" effects of switching between the fixed-base antennas. This process is handled automatically, of course, by link-level protocols carried over land-based control channels.
As everybody knows, GPS data will be used to make technical improvements to cellular service in the next round of upgrades to standard cellular technology. The addition of GPS data is government-mandated in our post-911 world, of course, to enable government "snooping". Though we have varied opinions about that, there can be no question that the GPS data could be used to enable a widening of personal-communications services. Inevitably, GPS data must be an integral part of next-generation link-control protocols.
We need to expand personal communications services. To do that, we need to develop our abilities to make fuller use of the frequency spectrum. Conversely, we need to be smarter about the means we employ to split up its allocation. In converse to that converse, then, we need protocols that allocate spectrum power to those who really need it - and only when they need it.
In suggesting various ways to do that, we must consider various variables to control:
effective radiated power of the transmitters
transmitter power
transmitter antenna directivity
transmitter antenna gain
transmitter antenna height
transmitter signal polarization
receiver antenna directivity
receiver antenna gain
receiver antenna height
receiver signal polarization
Transmitter Antenna height
We should position switchable, alternative antennas at various heights on a tall antenna tower (or on a skyscraper); select the antenna at the lowest height necessary to maintain an effective communications link, given the line-of-sight distances which must be spanned.
Transmitter Antenna Directivity
Make the antenna mounts rotate as required, to "point" along a distinct link-transmission-path.
Transmitter Antenna gain
Make the antenna gain selectable, by providing feeds to optional antenna-array elements.
Receiver gains and directivities
Any help from remote (personal, hand-held) devices (information on altitude, antenna gain or directivity) can be used to decrease the transmitter's effective radiated power requirements.
On the transmitter side, there may be ways to control the signal polarization. It could be harder to control this parameter on a hand-held remote receiver, but it's feasible if the remote antenna is mounted on a planar surface (like rooftop installations on cars or trucks).
That's not an exhaustive discussion of the topic, but it's enough to open a dialog. Any questions? Comments? I'd like to hear them:
Mark Mondt
2025 S Glendale
Wichita, KS 67218
mmondtsr@yahoo.com
or simply, hire me.
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