Posted on 10/07/2002 1:42:41 PM PDT by sourcery
CD's were invented by Sony. MA was invented by the Puritans, but became a wholly-owned subsidiary of the Kennedy family in a hostile buyout.
No, I did not say I had an old phone. I said this phone is considered an old model overseas. Here, it is the "latest and greatest." I've got a six year old Nokia that does more than this piece of garbage.
Look, the U.S. is way behind in the cell phone market. That is a fact. What is being passed off as new here is outdated compared to what is available overseas.
It is true that a secure transatlantic phone link was established during WW II between Roosevelt and Churchill that used mixers, filters, and a tone sequence recorded on a phonograph disk. The tone sequence rapidly modified the pitch of the speaker's voice so as to make it unintelligible without the decoding equipment, which was almost identical to the encoding gear and had to use an identical copy of the record (which was sent by military/diplomatic courier under heavy guard).
It was tricky to operate because the recordings had to be started at exactly the same time and run at exactly the same speed (which is still an issue with the code generators in modern digital systems).
Also helped build a 220 repeater out of an old exciter, receiver, and a TE Systems amp; it's in service on the mountain next to the 440.
Built a 1.2 GHz. repeater for the house out of a pair of Kenwood 541s and a RLC-Club controller... I use it to link to the repeaters on the mountain; from there I can link to other repeaters all over the state. I get about two miles of HT coverage (antenna is at 25 feet AGL) out of it, running one watt, with trees all over the place around here.
Fun stuff.
I fairly sure the concept of "code division" (a form of multiplex) was around at the end of WWII.Maybe on a few wireline circuits spanning the Atlantic (trans-Atlantic cable) ... but nothing involving radio ...
Wait - they used time division, not 'code' division on those 'circuits' ...
About the same for shared channel access arbitration (multiple access).Multiple access implies multiple users accessing a common channel concurrently (from the viewpoint of each subscriber). No arbitration ...
I fairly sure the concept of "code division" (a form of multiplex) was around at the end of WWII. About the same for shared channel access arbitration (multiple access).I'm not going to grant credit on this item - this sounds like pure speculation on your part ... certainly the topic 'spead spectrum' wasn't in common usage and even multiplex (either carrier or time-division) in telephony was young at this point - SSB (single side band wasn't even in use yet!) ... (the texts to check for references to these items would be the olf BSTJ - Bell System Techncal Journals - and not some poorly reseached science show hosted by a celebrity)
No points for you this evening ...
the U.S. is way behind in the cell phone market. That is a fact.A large part of your beef was with the quality of the service in the US -
- and poor quality should in no way translate into arguemnts that we are 'way behind'. Those are *two* different issues ... (I would point to the availability of the PocketNet browser in the AT&T markets that have been available for several years now and the recent color graphics browser and 144 KBit speeds available from Sprint as arguements against being 'way behind' too.)
As to your contention to wide-spread availability of service in China - I think this too is over-blown. Much hope by a number of manufacturers has been pinned on further contracts for infrastructure equipment for China and a standardization on a single air-interface standard: 1) TDMA/GSM, 2) CDMA2000 or 3) their own home-brewed "Time-Division spread-spectrum format" (I kid you not!) so I therefore conclude that China is not as built-out as you would tend to have us believe ...
Moto 80-D's?
We use those as jacks to prop-up trailered equipment when changing tires out on the property ...
I've got a six year old Nokia that does more than this piece of garbage.I doubt that - not at six years old ...
You are talking though your hat now ... there have been a variety of plans available through the years - some as reasonable as 66 cents a day plus 10 cents a minute for 'security' use ... my use during my time with a carrier was 'non-rev' (non-revenue generating since it was a company phone that was allowed to be used for personal calls as well).
So much for me (or the public) getting 'ripped off'.
Thanks for playing here on FR and be *sure* you put something in the kitty on your way out ...
The tone sequence rapidly modified the pitch of the speaker's voice so as to make it unintelligible without the decoding equipment, which was almost identical to the encoding gear and had to use an identical copy of the record
Ingenuis ... an analog scrambler using bear skins and stone knives!
What is the general description of MAP messaging?
(Note that the article says Cingular went GSM, but that's not the case in Texas.)A conversion to GPRS (GSM) has commenced withing the old Southwestern Bell Mobile Systems/Cingular network. It seems that thismis the next de facto standard for 800 MHz Cellular among the biggies ...
Now, I worked for Motorola since before there were cellphones and followed their development from the beginning. Although Motorola was slow--disastrously slow, as it turned out--to switch their product line to digital, they were an early exponent of CDMA. (They also faced reality and actively developed and promoted GSM products in Europe.)Moto *had* teamed with Nortel for awhile - then that marriage fell apart ...
At one point we picked up a an engineer from Moto named Michael Thomas who had been with one of the teams in Ft. Worth doing CDMA development - he didn't seem to think they were making much progress at the time.
Shortly thereafter I had a chance to 'optimize' and massage some cellular system parameters in a small Motorola sytem and was NOT impressed with the operation of the Moto switch OR the operation of base station cellular infrastructure equipment. It was not as completely instrumented and the data backhauled (signal strengths, current serving cell and sector number, etc) as the Ericsson RBS 882 equipment was.
I was puzzled why Cingular took this apparent step backward, from CDMA to TDMA; I must assume that there was much more TDMA infrastructure in place among the companies that made up Cingular, and therefore the CDMA companies had to switch.All of Bell's gear was TDMA (IS-54 then later IS-136). When they bought out somebody else they changed-out that gear (it seems).
Now, I'm wondering if Cingular will eventually scrap their TDMA and go to 3G (CDMA2K). I kind of hope so, at least if they'll swap my phone again <)B^).They have made commitments to go GPRS (GSM format).
Source:
FCC's SEVENTH REPORT to Congress
Adopted: June 13, 2002 Released: July 3, 2002
Excerpt:
Cingular Wireless/AT&T Wireless – In January 2002, Cingular Wireless and AT&T Wirele ss announced the formation of an infrastructure joint venture to build out a GSM/GPRS network along 3,000 miles of interstate highways predominantly in western and midwestern states.---
TDMA is being phased out as its main advocates, AT&T Wireless and Cingular Wireless, have announced plans to overlay their existing TDMA networks with GSM/GPRS technology.159 Furthermore, the trade group that had represented TDMA technology announced in December 2001 that it was dissolving, as it had “successfully served its mission.”160
AT&T Wireless still expects to use TDMA for many years, but as reported in the Sixth Report, the company announced plans to overlay GSM/GPRS on its TDMA network in order to improve its wireless data capabilities and enhance its migration to 3G technology.161 By the end of 2001, AT&T Wireless had rolled out GSM/GPRS to 45 percent of the POPs covered by its network.162 AT&T Wireless has also announced that it plans to deploy GSM/GPRS in the network that it recently acquired through the purchase of TeleCorp.163
Cingular Wireless, which currently has a mix of TDMA (covering 70 percent of its POPs) and GSM (covering 30 percent of its POPs) networks, announced in October 2001 that it would overbuild its entire TDMA and remaining analog networks with GSM/GPRS.164 Cingular Wireless expects to have 50 percent of its POPs covered with GSM by the end of 2002 and the remainder covered by the end of 2003.165 Cingular Wireless will continue to provide TDMA service to its current customers, but it expects that many will upgrade to its GSM technology over time.166 Cingular Wireless said the national network upgrade will cost approximately $3 billion.167 And, as noted above, Cingular Wireless and AT&T Wireless have announced plans to build a GSM/GPRS network along 3,000 miles of interstate highways in a number of western and midwestern states.168
As a result of these industry developments, this report no longer distinguishes between TDMA and GSM networks in its analysis of digital coverage, but considers the two as one migration path towards more advanced digital capabilities. We recognize that TDMA as currently deployed will continue to be used by millions of subscribers for a number of years. Of the other four nationwide mobile telephone operators, Sprint PCS and Verizon Wireless use CDMA as their digital technology, VoiceStream uses GSM, and Nextel uses iDEN.
What is not very well described in this article is the seperation between the cellular infrastrucure (which includes the base stations and base station control and access to the old-school public network) and what I like to think of as the traditional SS7 network (where MAP is used).
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