US6014375A
Expired / Lapsed
US
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TDMA radio protocol with adaptive vocoder selection
Assignee: Ericsson Inc
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Filing: 1997-02-13
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Granted: 2000-01-11
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Expires: 2017-02-13
Abstract
Abstract A new air interface protocol compliant with narrowband (12.5 kHz) channels being mandated for use in North America provides a narrowband (i.e., 18 kbps-19.2 kbps), two-slot scaled version of the European TETRA time division signaling that can accommodate different vocoder frame formats. Any vocoder having a frame size that is a submultiple of a certain frame rate can be used. The new air interface is fully compatible with prior frequency division signaling control channels. Adaptive vocoder selection can allow a radio to dynamically select between different vocoding standards and indicate its selection through over-the-air signaling.
Inventors
- 👤 William O. Janky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 02:21
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/24; H04B7/26; H04B7/2643
Claims Analysis
Total Claims: 56
Claim 1
Independent Claim
117 words
A method of communicating radio signals over the air comprising: (a) transmitting a version of the TETRA time division signaling over a radio channel, said version of the TETRA time division signaling being scaled for transmission over a narrowband channel; (b) accommodating any of plural vocoder frame formats within said transmitted signaling; and (c) synchronizing the transmitted signaling with a frequency division digital control channel, wherein the transmitting step (a) comprises transmitting a two-slot narrowbanded version of the TETRA signaling, said two-slot narrowbanded version including a two-slot frame structure and further including slow associated control channel bits grouped at the beginning of the two-slot frame structure to provide settling time required for full duplex two-slot TDMA communication.
Claim 2
Independent Claim
117 words
A method of communicating radio signals over the air comprising: (a) transmitting a version of the TETRA time division signaling over a radio channel, said version of the TETRA time division signaling being scaled for transmission over a narrowband channel; (b) accommodating any of plural vocoder frame formats within said transmitted signaling; and (c) synchronizing the transmitted signaling with a frequency division digital control channel, wherein the transmitting step (a) comprises transmitting a two-slot narrowbanded version of the TETRA signaling, said two-slot narrowbanded version including a two-slot frame structure and further including slow associated control channel bits grouped at the beginning of the two-slot frame structure to provide settling time required for full duplex two-slot TDMA communication.
Claim 3
Dependent Claim
26 words
A method as in claim 1 wherein the transmitting step (a) comprises transmitting the signaling substantially at the data rate of 18 kbps to 19.2 kbps.
Claim 4
Dependent Claim
26 words
A method as in claim 1 wherein the transmitting step (a) comprises transmitting the signaling over a channel having a maximum bandwidth of substantially 12.5 kHz.
Claim 5
Dependent Claim
20 words
A method as in claim 1 wherein the accommodating step (b) includes accommodating at least one IMBE vocoder frame format.
Claim 6
Dependent Claim
28 words
A method as in claim 1 wherein the synchronizing step (c) comprises synchronizing the transmitted signaling with a frequency division digital control channel transmitted substantially at 9.6 kbps.
Claim 7
Dependent Claim
34 words
A method as in claim 1 wherein the transmitting step (a) includes transmitting a sequence of scaled, narrowbanded TETRA time division digital slots that are periodically synchronized with the digital control channel downlink signaling.
Claim 8
Dependent Claim
31 words
A method as in claim 1 wherein transmitting step (a) includes transmitting first and second blocks of digitized speech within the slot/frame, each digitized speech block comprising one-and-a-half vocoder speech frames.
Claim 9
Dependent Claim
17 words
A method as in claim 7 wherein each of the first and second blocks comprises 216 bits.
Claim 10
Dependent Claim
27 words
A method as in claim 8 further including accommodating smaller vocoder speech frames by padding at least some of the 216 bits within each digitized speech block.
Claim 11
Dependent Claim
22 words
A method as in claim 1 wherein transmitting step (a) includes transmitting three IMBE vocoder frames within each time division multiplexed slot.
Claim 12
Dependent Claim
30 words
A method as in claim 1 wherein transmitting step (a) includes transmitting a 510-bit slot substantially at 19.2 kbps, and appending plural pad bits at the end of the slot.
Claim 13
Dependent Claim
22 words
A method as in claim 11 wherein the appending step includes appending 34 pad bits to the end of the 510-bit slot.
Claim 14
Dependent Claim
52 words
A method as in claim 1 wherein the transmitting step includes transmitting: (i) a power control field, then (ii) a tail field, then (iii) a first digitized speech block, then (iv) a sync field, then (v) a second digitized speech block, then (vi) a tail field, and then (vii) a guard field.
Claim 15
Dependent Claim
68 words
A method as in claim 1 wherein the transmitting step includes transmitting: (i) a 30 to 34 bit power control field, then (ii) a 4 bit tail field, then (iii) a 216 bit first digitized speech block, then (iv) a 22 bit sync field, then (v) a 216 bit second digitized speech block, then (vi) a 4 bit tail field, and then (vii) a 14 bit guard field.
Claim 16
Independent Claim
87 words
A method of communicating radio signals over the air comprising: (a) transmitting a version of the TETRA time division signaling over a radio channel, said version of the TETRA time division signaling being scaled for transmission over a narrowband channel; (b) accommodating any of plural vocoder frame formats within said transmitted signaling; and (c) synchronizing the transmitted signaling with a frequency division digital control channel, wherein the transmitting step (a) includes transmitting a vocoder type field indicating which of the plural vocoder frame formats is in use.
Claim 17
Independent Claim
87 words
A method of communicating radio signals over the air comprising: (a) transmitting a version of the TETRA time division signaling over a radio channel, said version of the TETRA time division signaling being scaled for transmission over a narrowband channel; (b) accommodating any of plural vocoder frame formats within said transmitted signaling; and (c) synchronizing the transmitted signaling with a frequency division digital control channel, wherein the transmitting step (a) includes transmitting a vocoder type field indicating which of the plural vocoder frame formats is in use.
Claim 18
Independent Claim
120 words
A method of communicating radio signals over the air comprising: (a) transmitting a version of the TETRA time division signaling over a radio channel, said version of the TETRA time division signaling being scaled for transmission over a narrowband channel; (b) accommodating any of plural vocoder frame formats within said transmitted signaling; and (c) synchronizing the transmitted signaling with a frequency division digital control channel, wherein the transmitting step (a) includes transmitting a sequence of scaled, narrowbanded TETRA time division digital slots that are periodically synchronized with the digital control channel downlink signaling, and wherein the step of transmitting a sequence of slots/frames includes the step of aligning every ninth time division slot/frame with every seventeenth digital control channel frame.
Claim 19
Independent Claim
120 words
A method of communicating radio signals over the air comprising: (a) transmitting a version of the TETRA time division signaling over a radio channel, said version of the TETRA time division signaling being scaled for transmission over a narrowband channel; (b) accommodating any of plural vocoder frame formats within said transmitted signaling; and (c) synchronizing the transmitted signaling with a frequency division digital control channel, wherein the transmitting step (a) includes transmitting a sequence of scaled, narrowbanded TETRA time division digital slots that are periodically synchronized with the digital control channel downlink signaling, and wherein the step of transmitting a sequence of slots/frames includes the step of aligning every ninth time division slot/frame with every seventeenth digital control channel frame.
Claim 20
Independent Claim
80 words
A method of communicating radio signals over the air comprising: (a) transmitting a version of the TETRA time division signaling over a radio channel, said version of the TETRA time division signaling being scaled for transmission over a narrowband channel; (b) accommodating any of plural vocoder frame formats within said transmitted signaling; and (c) synchronizing the transmitted signaling with a frequency division digital control channel, wherein transmitting step (a) includes transmitting at least one vocoder type field within the slot/frame.
Claim 21
Independent Claim
80 words
A method of communicating radio signals over the air comprising: (a) transmitting a version of the TETRA time division signaling over a radio channel, said version of the TETRA time division signaling being scaled for transmission over a narrowband channel; (b) accommodating any of plural vocoder frame formats within said transmitted signaling; and (c) synchronizing the transmitted signaling with a frequency division digital control channel, wherein transmitting step (a) includes transmitting at least one vocoder type field within the slot/frame.
Claim 22
Independent Claim
113 words
A method of operating a digital radio within a radio system having a frequency division control channel including an uplink and a downlink, the method comprising: (a) transmitting a channel request message on the frequency division control channel uplink; (b) receiving a channel assignment message over the frequency division control channel downlink, the received channel assignment message indicating an assigned time division working channel; and (c) at least in part in response to the received channel assignment message, transmitting at least one TETRA time division digital slot/frame scaled for narrowband transmission on the assigned time division working channel, wherein transmitting step (c) includes transmitting at least one vocoder type field within the slot/frame.
Claim 23
Independent Claim
113 words
A method of operating a digital radio within a radio system having a frequency division control channel including an uplink and a downlink, the method comprising: (a) transmitting a channel request message on the frequency division control channel uplink; (b) receiving a channel assignment message over the frequency division control channel downlink, the received channel assignment message indicating an assigned time division working channel; and (c) at least in part in response to the received channel assignment message, transmitting at least one TETRA time division digital slot/frame scaled for narrowband transmission on the assigned time division working channel, wherein transmitting step (c) includes transmitting at least one vocoder type field within the slot/frame.
Claim 24
Dependent Claim
34 words
A method as in claim 18 wherein the transmitting step (c) includes transmitting a sequence of scaled, narrowbanded TETRA time division digital slots that are periodically synchronized with the digital control channel downlink signaling.
Claim 25
Dependent Claim
32 words
A method as in claim 19 wherein the step of transmitting a sequence of slots/frames includes the step of aligning every ninth time division slot/frame with every seventeenth digital control channel frame.
Claim 26
Dependent Claim
43 words
A method as in claim 18 wherein the assigned time division working channel has a maximum bandwidth of about 12.5 kHz, and transmitting step (c) comprises transmitting the digital slot/frame at a maximum data rate of between about 18 kbps and 19.2 kbps.
Claim 27
Dependent Claim
31 words
A method as in claim 18 wherein transmitting step (c) includes transmitting first and second blocks of digitized speech within the slot/frame,, each digitized speech block comprising one-and-a-half vocoder speech frames.
Claim 28
Dependent Claim
17 words
A method as in claim 22 wherein each of the first and second blocks comprises 216 bits.
Claim 29
Dependent Claim
27 words
A method as in claim 23 further including accommodating smaller vocoder speech frames by padding at least some of the 216 bits within each digitized speech block.
Claim 30
Dependent Claim
19 words
A method as in claim 18 wherein transmitting step (c) includes transmitting three IMBE vocoder frames within the slot.
Claim 31
Dependent Claim
30 words
A method as in claim 18 wherein transmitting step (c) includes transmitting a 510-bit slot substantially at 19.2 kbps, and appending plural pad bits at the end of the slot.
Claim 32
Dependent Claim
22 words
A method as in claim 26 wherein the appending step includes appending 34 pad bits to the end of the 510-bit slot.
Claim 33
Dependent Claim
52 words
A method as in claim 18 wherein the transmitting step includes transmitting: (i) a power control field, then (ii) a tail field, then (iii) a first digitized speech block, then (iv) a sync field, then (v) a second digitized speech block, then (vi) a tail field, and then (vii) a guard field.
Claim 34
Dependent Claim
68 words
A method as in claim 18 wherein the transmitting step includes transmitting: (i) a 30 to 34 bit power control field, then (ii) a 4 bit tail field, then (iii) a 216 bit first digitized speech block, then (iv) a 22 bit sync field, then (v) a 216 bit second digitized speech block, then (vi) a 4 bit tail field, and then (vii) a 14 bit guard field.
Claim 35
Dependent Claim
42 words
A method as in claim 18 wherein said step (c) comprises transmitting a two-slot frame structure including slow associated control channel bits grouped at the beginning of the two-slot frame structure to provide settling time required for full duplex two-slot TDMA communication.
Claim 36
Independent Claim
52 words
A method of operating a radio comprising: (a) receiving a time division multiplexed signaling slot on an RF uplink, the slot including a vocoder type code indicating a vocoder type; and (b) encoding the vocoder type with slow associated control channel bits transmitted within time division multiplexed signaling over an RF downlink.
Claim 37
Independent Claim
52 words
A method of operating a radio comprising: (a) receiving a time division multiplexed signaling slot on an RF uplink, the slot including a vocoder type code indicating a vocoder type; and (b) encoding the vocoder type with slow associated control channel bits transmitted within time division multiplexed signaling over an RF downlink.
Claim 38
Dependent Claim
37 words
A method as in claim 31 wherein the encoding step (b) includes indicating whether the transmitted time division multiplexed signaling includes 7.1 kbps IMBE vocoded speech, 7.2 kbps IMBE vocoded speech, or 7.2 kbps Thomson vocoded speech.
Claim 39
Independent Claim
69 words
A method of upgrading a frequency division radio system to provide a time division multiplexed working channel air interface, the method comprising: (a) installing at least one repeater capable of transmitting and receiving a two-slot 12.5 kHz version of TETRA signaling scaled for transmission over a 12.5 KHz narrowband transmission channel; and (b) synchronizing the two-slot 12.5 kHz scaled version of TETRA signaling with frequency division control channel signaling.
Claim 40
Independent Claim
69 words
A method of upgrading a frequency division radio system to provide a time division multiplexed working channel air interface, the method comprising: (a) installing at least one repeater capable of transmitting and receiving a two-slot 12.5 kHz version of TETRA signaling scaled for transmission over a 12.5 KHz narrowband transmission channel; and (b) synchronizing the two-slot 12.5 kHz scaled version of TETRA signaling with frequency division control channel signaling.
Claim 41
Dependent Claim
48 words
A method as in claim 33 wherein the two-slot 12.5 kHz scaled narrowbanded version of TETRA signaling includes a two-slot frame structure including slow associated control channel bits grouped at the beginning of the two-slot frame structure to provide settling time required for full duplex two-slot TDMA communication.
Claim 42
Dependent Claim
88 words
In a method of communicating a digital time division signaling slot over a radio channel comprising: (a) transmitting a power amplifier ramp field; (b) transmitting tail bits; (c) transmitting a first vocoded speech block; (d) transmitting a sync field; (e) transmitting a second vocoded speech block; (f) transmitting additional tail bits; and (g) transmitting guard bits, an improvement comprising: (i) transmitting vocoder type information within the slot, and (ii) using the vocoder type information to select between first and second differing vocoder formats for said vocoded speech block.
Claim 43
Dependent Claim
88 words
In a method of communicating a digital time division signaling slot over a radio channel comprising: (a) transmitting a power amplifier ramp field; (b) transmitting tail bits; (c) transmitting a first vocoded speech block; (d) transmitting a sync field; (e) transmitting a second vocoded speech block; (f) transmitting additional tail bits; and (g) transmitting guard bits, an improvement comprising: (i) transmitting vocoder type information within the slot, and (ii) using the vocoder type information to select between first and second differing vocoder formats for said vocoded speech block.
Claim 44
Independent Claim
68 words
A method of transmitting a digital time division signaling slot over a radio channel comprising: (a) transmitting a power amplifier ramp field, then (b) transmitting a vocoder type field, then (c) transmitting tail bits, then (d) transmitting a first vocoded speech block, then (e) transmitting a sync field, then (f) transmitting a second vocoded speech block, then (g) transmitting additional tail bits; and then (h) transmitting guard bits.
Claim 45
Independent Claim
68 words
A method of transmitting a digital time division signaling slot over a radio channel comprising: (a) transmitting a power amplifier ramp field, then (b) transmitting a vocoder type field, then (c) transmitting tail bits, then (d) transmitting a first vocoded speech block, then (e) transmitting a sync field, then (f) transmitting a second vocoded speech block, then (g) transmitting additional tail bits; and then (h) transmitting guard bits.
Claim 46
Independent Claim
105 words
A method of upgrading an existing frequency division multiplexed trunked radio communication system to accommodate time division multiplexed digital communications while preserving compatibility with existing radios incapable of transmitting or receiving time division multiplexed digital communications, the method including: installing, within the system, at least one new repeater capable of transmitting a two-slot time division multiplexed version of TETRA digital signaling scaled for narrowband transmission within a 12.5 kHz channel bandwidth; and selectively assigning the new repeater to handle radio calls substantially without assigning the new repeater to handle calls for radios incapable of transmitting or receiving the scaled TETRA time division multiplexed digital communications.
Claim 47
Independent Claim
105 words
A method of upgrading an existing frequency division multiplexed trunked radio communication system to accommodate time division multiplexed digital communications while preserving compatibility with existing radios incapable of transmitting or receiving time division multiplexed digital communications, the method including: installing, within the system, at least one new repeater capable of transmitting a two-slot time division multiplexed version of TETRA digital signaling scaled for narrowband transmission within a 12.5 kHz channel bandwidth; and selectively assigning the new repeater to handle radio calls substantially without assigning the new repeater to handle calls for radios incapable of transmitting or receiving the scaled TETRA time division multiplexed digital communications.
Claim 48
Dependent Claim
49 words
A method as in claim 37 wherein the two-slot time division multiplexed scaled version of TETRA digital signaling includes a two-slot frame structure including slow associated control channel bits grouped at the beginning of the two-slot frame structure to provide settling time required for full duplex two-slot TDMA communication.
Claim 49
Independent Claim
135 words
A method of upgrading an existing frequency division multiplexed trunked radio communication system to accommodate time division multiplexed digital communications while preserving compatibility with existing radios incapable of transmitting or receiving time division multiplexed digital communications, the system including at least one existing frequency division working channel repeater, the method including: installing, within the system, at least one new repeater capable of transmitting a two-slot time division multiplexed version of TETRA digital signaling scaled for narrowband transmission within a 12.5 kHz channel bandwidth; selectively assigning the new repeater to handle radio calls for radios capable of transmitting or receiving time division multiplexed scaled narrowbanded version of TETRA digital communications; and selectively assigning the existing repeater to handle radio calls for radios not capable of transmitting or receiving time division multiplexed scaled narrowbanded TETRA digital communications.
Claim 50
Independent Claim
135 words
A method of upgrading an existing frequency division multiplexed trunked radio communication system to accommodate time division multiplexed digital communications while preserving compatibility with existing radios incapable of transmitting or receiving time division multiplexed digital communications, the system including at least one existing frequency division working channel repeater, the method including: installing, within the system, at least one new repeater capable of transmitting a two-slot time division multiplexed version of TETRA digital signaling scaled for narrowband transmission within a 12.5 kHz channel bandwidth; selectively assigning the new repeater to handle radio calls for radios capable of transmitting or receiving time division multiplexed scaled narrowbanded version of TETRA digital communications; and selectively assigning the existing repeater to handle radio calls for radios not capable of transmitting or receiving time division multiplexed scaled narrowbanded TETRA digital communications.
Claim 51
Dependent Claim
26 words
A method as in claim 39 further including the step of adapting the new repeater during operation to either of two different, predefined vocoded speech formats.
Claim 52
Dependent Claim
34 words
A method as in claim 39 wherein the system includes a frequency division control channel repeater, and the method further includes synchronizing transmissions of the new repeater with transmissions of the control channel repeater.
Claim 53
Dependent Claim
39 words
A method as in claim 41 wherein the synchronizing step includes aligning a time division frame edge transmitted by the new repeater with a control channel frame edge transmitted by the control channel repeater once substantially every 510 ms.
Claim 54
Dependent Claim
49 words
A method as in claim 39 wherein the two-slot time division multiplexed scaled version of TETRA digital signaling includes a two-slot frame structure including slow associated control channel bits grouped at the beginning of the two-slot frame structure to provide settling time required for full duplex two-slot TDMA communication.
Claim 55
Dependent Claim
52 words
In a radio communications system using a two-slot time division multiplexed frame structure, an improvement comprising grouping slow associated control channel (SAACH) bits and positioning them before an initial sync field at the beginning of the two-slot frame structure to provide settling time required for full duplex two-slot TDMA 12.5 kHz communication.
Claim 56
Dependent Claim
52 words
In a radio communications system using a two-slot time division multiplexed frame structure, an improvement comprising grouping slow associated control channel (SAACH) bits and positioning them before an initial sync field at the beginning of the two-slot frame structure to provide settling time required for full duplex two-slot TDMA 12.5 kHz communication.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-01-10 | 2003-07-12 | 2004-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-01-10 | 2007-07-12 | 2008-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-01-10 | 2011-07-12 | 2012-01-11 | $7700.00 | Window Closed / Lapsed |