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IS-54, on the other hand, increased capacity by digital means using TDMA protocols.
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IS-54 and on
That name is based on the abbreviation for time division multiple access, a common multiple access technique which is used by multiple protocols, including GSM, as well as in IS-54 and IS-136.
IS-54 was, in fact, backward compatible with analog cellular and indeed co-exists on the same radio channels as AMPS.
IS-54 and by
Time Division Multiple Access or TDMA was initially defined by the IS-54 standard and is now specified in the IS-13x series of specifications of the EIA / TIA.
IS-54 and digital
IS-54 stands for Interim Standard-54, which is a mobile communication standard employing digital technology.
The access method used for IS-54 is Time Division Multiple Access ( TDMA ), which was the first U. S. digital standard to be developed.
IS-54 and TDMA
IS-54 is the first mobile communication system which had provision for security, and the first to employ TDMA technology.
IS-54 and .
IS-136 added a number of features to the original IS-54 specification, including text messaging, circuit switched data ( CSD ), and an improved compression protocol.
The ANSI designation of IS-54 is ANSI / TIA / EIA-627, but this standard is still popularly referred to as IS-54.
IS-54 employs the same 30 kHz channel spacing and frequency bands ( 824-849 and 869-894 MHz ) as AMPS.
To maintain compatibility with the existing AMPS cellular telephone system, the primary forward and reverse control channels in IS-54 cellular systems use the same signaling techniques and modulation scheme ( binary FSK ) as AMPS.
The IS-54 system has different synchronization sequences for each of the six time slots making up the frame, thereby allowing each receiver to synchronize to its own preassigned time slots.
The modulation scheme for IS-54 is 7C / 4 differential quaternary phase shift keying ( DQPSK ), otherwise known as differential 7t / 4 4-PSK or π / 4 DQPSK.
IS-54 security features is also a matter of interest as it was the first standard to specify some security measures.
IS-54 uses the CAVE ( Cellular Authentication, Voice Privacy and Encryption ) algorithm for authentication and the CMEA ( Cellular Message Encryption Algorithm ) for encryption.
Variations of this codec have been used in several 2G cellular telephony standards, including IS-54, IS-136 ( D-AMPS ), GSM ( Half Rate speech ) and iDEN.
on and other
But if they really hoped to succeed they needed professionals, men who knew how to use a gun against men, who would match the killers on the other side.
I seized the rack and made a western-style flying-mount just in time, one of my knees mercifully landing on my duffel bag -- and merely wrecking my camera, I was to discover later -- my other knee landing on the slivery truck floor boards and -- but this is no medical report.
Two uniformed officers, a couple of plain-clothesmen I knew, and two other men stood on a gray cement area next to the pool on my left.
Thirty minutes later, the outrigger grated on sand and other girls, waiting on shore, rushed forward to pull it up on the beach and make it fast with vine ropes to a large boulder.
The Brahmaputra has its headwaters in the tableland of the world, the towering white headwalls of the Himalayas that are unknown to man as any other space on the planet.
He bounced exuberantly on the sagging bed and was even more delighted when Madame Lalaurie -- after closing the door -- showed the slave that the bed was designed for something other than slumber.
The lives so many of them gave, to forestall what they believed would be a fatal encroachment by the Union on the powers reserved to their states have continued ever since to safeguard all Americans against freedom's other foe.
Otherwise, we go on endlessly trying to draw the line, color and other, as to which kind of man we wish to see dominate.
Research, on the other hand, has shown many stepmothers to be eminently successful, some far better than the real mothers.
But because it is the function of the mind to turn the one into the other by means of the capacities with which words endow it, we do not unwisely examine the type of distinction, in the sphere of politics, on which decisions hang.
Mother and son recognize each other and, in Mann's version of this legend, make a remarkable confession of guilt to each other, the confession of unconscious motive and unconscious knowledge of their true identities from the time they had first set eyes on each other.
A useful comment on his relation to his region may be made, I think, by noting briefly how in handling Southern materials and Southern problems he has deviated from the pattern set by other Southern authors while remaining faithful to the essential character of the region.
As a consequence of the tensions thus produced in his thoughts and feelings, he wrote on the one hand sketches of idealized hunting trips and on the other an anecdote of the village of Hardscrabble, Arkansas, where no one had ever seen a piano ; ;
on and hand
He had taken a carbine down from the wall and it trailed from his hand, the stock bumping on the wood floor.
Rod shifted his eager eyes from the milling group out in the circle long enough to reply, `` I ain't much of a hand for Dare-Base and Farmer-in-the-Dell, but I'd sure like to get in on the handhold and wrestles ''.
Less assured than the tall, wide-shouldered man in the lead, Cobb followed alertly, a hand on his gun butt.
But with her hand softly on his cheek for a last moment, she closed the door and he went back down the hall and into his bed excited, expectant, and finally faintly grinning with the feel of her hand against his mouth.
He didn't stop till he was within three feet of Blue Throat and by that time the gang leader's right hand was on the butt of his revolver.
While she was struggling to get her skirt down and get on her feet again, Jack ran over, offered her his hand and said, `` Gosh, I'm sorry, Miss Langford.
When her hand touched his, fire went through Jack and he felt weak, but he managed somehow to get her on her feet.
Despite this danger, however, we are informed on every hand that ideas, not machines, are our finest tools ; ;
Alone, rejected on every hand, divorced, and in financial trouble, he leaped from an eleventh-floor window of the Abbey Hotel in 1937.
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