Browse Prior Art Database

ALGORITHM TO PROVIDE DYNAMIC CHANNEL ALLOCATION OF 3:l RESOURCES

IP.com Disclosure Number: IPCOM000008334D
Original Publication Date: 1997-Sep-01
Included in the Prior Art Database: 2002-Jun-06
Document File: 5 page(s) / 301K

Publishing Venue

Motorola

Related People

Patrick J. Keegan: AUTHOR [+3]

Abstract

The iDEN system is based on the Time Division Multiple Access (TDMA) paradigm. In such a system, one frequency is divided into multiple time slots allowing several logical channels to coexist on the same frequency.

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MOTVROLA Technical Developments

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ALGORITHM TO PROVIDE DYNAMIC CHANNEL ALLOCATION OF 3:l RESOURCES

by Patrick J. Keegan, Matthew W. Simpson and Gary J. Goethals

INTRODUCTION

  The iDEN system is based on the Time Division Multiple Access (TDMA) paradigm. In such a system, one frequency is divided into multiple time slots allowing several logical channels to coexist on the same frequency.

  The iDEN system divides each of its frequencies into twenty-four logical slots, where each slot belongs to one and only one logical channel. Each logical channel has a starting slot and interleave. The interleave refers to the channef's occupancy of every nth slot (of the original twenty-four). For example a channel having an interleave of three (3: I) will occupy every third slot of the twenty-four. Dividing twenty-four by the interleave (three) we see that a 3: I resource will occupy eight slot,s.

  The iDEN system currently supports three inter- leave types: twelve, six and three. To complete our example, an interleave twelve channel (12: 1) occupies every twelfth slot for a total of two. Lastly an inter- leave six channel (6: 1) occupies every sixth slot of the frequency for a total of four slots per 6: I channel.

Logically then, we can say that as long as one

channel's slots do not overlap another's and the total number of all the channels' slots equal twenty four, we have the basics of placing multiple logical channels on one frequency.

  There are many combinations of channels that may coexist. For example, one may have three 3:l channels on the same frequency, or one 3:l and four 6:l channels (Figure la), how or even two 3:1's, one 6: 1, and two 12: l's (Figure 1 b), so long as the total slots occupied by all the channels are equal to twenty four. Note in the figures below the notation uses an 'I' for a 3: 1 channel, a 'T' for a 6: 1 channel and a 'D' for a 12: 1 channel and the number follow- ing the letter indicates the originality.

LOGICAL CHANNEL SPLITS AND JOINS

  If one looks closely at Figure la, one will notice immediately that though this configuration is valid, it is not very practical in many applications. If a frequency was divided up as in Figure la, what would be the result if more than one 3:l or a 12:1 resource was needed for some application? The obvious (but incorrect) answer is that the user would be denied the request for a second 3:l or 12: I resource.

I 2 3 4 5 6 7 8 9 10 II 12 13 14 I5 16 17 I8 19 20 21 22 23 24

II Tl T2 II T3 T4 II Tl T2 II T3 T II Tl T II T3 T4 II Tl T2 11 T3 T4

Fig. la One 3: 1 and four 6: I channels on the the same frequency.

I 2 3 4 5 6 7 8 9 10 II I2 I3 14 15 16 I7 18 19 20 21 22 23 24

II 12 Dl 11 I2 Tl II 12 D2 II 12 Tl II 12 Dl II I2 TI II 12 D2 I1 12 Tl

Fig. lb Two 3: 1, one 6: I and two 12: I channels on the same frequency.

u> MOIOrOla. 1°C. 1997 128 September 1997

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m MOTOROLA Technical Developments

away and split into 12:I resou...