CN101226675A - Wireless wide-area system for calling for help - Google Patents
Wireless wide-area system for calling for help Download PDFInfo
- Publication number
- CN101226675A CN101226675A CNA2008100652052A CN200810065205A CN101226675A CN 101226675 A CN101226675 A CN 101226675A CN A2008100652052 A CNA2008100652052 A CN A2008100652052A CN 200810065205 A CN200810065205 A CN 200810065205A CN 101226675 A CN101226675 A CN 101226675A
- Authority
- CN
- China
- Prior art keywords
- distress call
- help
- calling
- information
- shortwave
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Position Fixing By Use Of Radio Waves (AREA)
- Circuits Of Receivers In General (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
The invention discloses a wireless wide area calling system, which comprises a user terminal and calling receiving stations distributed everywhere. The user terminal is used to send out short-wave and continuous wave calling signals including information of caller, information of bailer and information of geographic position of the user terminal. The receiving stations are used to receive the calling signal of the user terminal and deliver the calling signal to the assigned bailer in the calling signal. The invention is a convenient wireless wide area calling system with low cost and easy construction.
Description
Technical field
The present invention relates to wireless wide-area system for calling for help, relate in particular to a kind of radio wide-area system for calling for help that uses the shortwave frequency range.
Background technology
People meet with disaster or unexpected dangerous situation, and in the time of only can't escaping danger with the strength of self, valid approach is exactly oneself the accurate geographic position to other people emergency and announcement, as relatives, friend or specific relief group etc.And the problem of standing in the breach then is how to get in touch, to send an SOS with the external world.
Develop rapidly along with mechanics of communication, GSM, CDMA, PHS, global magnitude public correspondence net occur in succession, in these network's coverage areas, when people are in danger, can directly use the communication terminal of carrying to send out a signal for help to specific object, wait for rescue by above-mentioned network.But, if earthquake takes place, floods, fire, burst fire-disasters such as the attack of terrorism are destroyed communication network, perhaps the above-mentioned general communication network coverage less than remote districts, as enter foreign environment, drive to go on a journey, ground observation is explored, tourism, likelihood ratio condition with higher in danger such as children old man goes out, its zone of action often be exactly the above-mentioned general communication network coverage less than remote districts, therefore, when people are in danger, often because can't send an SOS and extraneous getting in touch maybe can't make the external world know the accurate geographic position of oneself and incur loss through delay rescue opportunity, thereby cause the heavy losses of aspects such as the person or property safety.
Summary of the invention
Technical matters to be solved by this invention is: a kind of low cost, wireless wide-area system for calling for help easily are provided.
For solving the problems of the technologies described above, the present invention adopts following technical scheme:
A kind of wireless wide-area system for calling for help comprises:
User terminal is used to send the shortwave continuous wave distress call of the calling for help person's information that carries, clientage's information and this user terminal geographical location information;
Be distributed in keeping of various places and listen platform, be used to receive the distress call of described user terminal, and described distress call notified the clientage of appointment in the distress call.
Correspondingly, the present invention also provides a kind of radio formula to call for help terminal, comprises the short wave receiver that is used to receive the signal of launching in the shortwave broadcasting radio station, also includes:
Geographical location information obtains device, is used for obtaining from GPS the geographical location information of this calling for help terminal seat;
The distress call emitter is used to launch the shortwave continuous wave distress call that adopts the Morse code form, and described distress call comprises calling for help person's information, clientage's information and geographical location information.
Correspondingly, the present invention also provides a kind of distress call receiving trap, be used to receive the shortwave continuous wave signal, this device comprises multiple filter and the multistage local oscillator that is set in turn in the circuit, and described multistage frequency wave filter is that narrow band filter or ultra-narrow bandwidth filter, a described local oscillator are VCXO and also are provided with a narrow band filter at its output terminal.
The invention has the beneficial effects as follows:
Embodiments of the invention send by the ham radio frequency in the radiothermy frequency range and receive distress call, built a kind of low cost, be easy to structure, wireless wide-area system for calling for help easily.
The present invention is described in further detail below in conjunction with accompanying drawing.
Description of drawings
Fig. 1 is the organization chart of an embodiment of wireless wide-area system for calling for help provided by the invention.
Fig. 2 is the circuit theory diagrams of an embodiment of radio formula transceiver terminal in the wireless wide-area system for calling for help provided by the invention.
Fig. 3 is the circuit theory diagrams of distress call receiving trap first embodiment in the wireless wide-area system for calling for help provided by the invention.
Fig. 4 keeps the schematic diagram of listening platform scanning cladding process in the wireless wide-area system for calling for help provided by the invention.
Fig. 5 is the circuit theory diagrams of distress call receiving trap second embodiment in the wireless wide-area system for calling for help provided by the invention.
Fig. 6 is the adjustment schematic diagram of distress call receiving trap second embodiment in the wireless wide-area system for calling for help provided by the invention.
Embodiment
Embodiments of the invention are that the ham radio emission frequency in the radiothermy sends and receive continuous wave (Continuous Wave, CW) network system of distress signal.Rough division of amateurish shortwave frequency range and propagation law are as follows:
40m wave band (7.000-7.100MHz): several hundred kilometers can be passed daytime and long distance can be passed night, but the crowded big length of antenna of noise.
20m wave band (14.000-14.350MHz): be subjected to solar activity and seasonal effect less, suitable long apart from transmission, antenna is shorter.
15m wave band (21.000-21.450MHz): be subjected to round the clock with the four seasons influence bigger, suitable in, long apart from transmission, antenna is short.
During specific implementation, consider to help long propagation, guarantee that but the four seasons all communications round the clock, the noisy sound of frequency range are little, emitting antenna is convenient to factors such as simplification as far as possible, can from 20m wave band and 15m wave band, respectively select frequency F1, a F2 special-purpose transmission frequency as present embodiment.
With reference to figure 1, this figure is the organization chart of an embodiment of wireless wide-area system for calling for help provided by the invention; As shown in the figure, this system comprises:
Be distributed in keeping of various places and listen platform 2, its major function is the distress call that receives described user terminal, and described distress call is notified the clientage 3 of appointment in the distress call.
In addition, this system can also comprise shortwave broadcasting radio station 4, and its major function is the user terminal that clientage's rescue information is sent to the calling for help people with the form of broadcasting.
During specific implementation, described user terminal 1 can be a radio formula transceiver terminal, and with reference to figure 2, this figure is the composition structural drawing of the radio formula transceiver terminal that provides of present embodiment; As shown in the figure, it has comprised the short wave receiver 11 that is used to receive the signal of launching in the shortwave broadcasting radio station; Also include geographical location information and obtain device 12, its major function is that (Globe Positioning System GPS) obtains the geographical location information of this calling for help terminal seat from GPS; And distress call emitter 13, being used to launch the continuous wave distress call that adopts the Morse code form, described distress call comprises calling for help person's information, clientage's information and geographical location information.
This user terminal also have one section can be by switch control the about 10m of length tiltedly draw antenna (neat primary antenna End-Fed Dipole), in the ordinary course of things, it can be used as a small and exquisite portable radio formula terminal and uses, when in danger, after ejecting described antenna by tractive or by trigger switch, launch CW Morse newspaper with miniwatt automatically at ham radio frequency F1 or F2 by this antenna.This message is with QRP (the radio q-signal of 2-3W, refer to the miniwatt emission, promptly CW is less than 5W, the SSB peak power emission less than 10W) the speed running fire of power and 20wpm 3 times, when accounting for about more than 50 seconds at every turn, per two minor ticks 3 seconds, manual intervention can repeat to send out again after 3 times.
Described message format is:
SOS?SOS?SOS?DE?HBS?X1?X2?X3?X4?SOS?E?X5/X6/X7N?X8/X9/Xa?SOS
Wherein, except that Morse reported set form, the information content of each code representative was as follows:
X1: the equipment user name Chinese phonetic alphabet;
X2: equipment user the country one belongs to direct distarce dialing area code is 86 as China;
X3: equipment user domestic direct dial area code is 0755 as Shenzhen;
X4: clientage's telephone number, promptly captive wish to keep listen a platform to receive this distress signal after, inform by telephone this " clientage " at once and initiate rescue action by the contact of " clientage " full powers;
X5, X6, X7: stranded some GPS longitude information, promptly east longitude X5 degree X6 divides X7 second;
X8, X9, Xa: stranded some GPS latitude information, promptly north latitude X8 degree X9 divides Xa second.
Wherein, X5-Xa obtains device 12 by described geographical location information and records in real time, and it is default that X1-X4 is all the equipment owner, for the purpose of more insuring, a plurality of clientages can also be set.
For example: Mr. Li Yimin occupies Shenzhen, and home phone number is 0755-00000000, buy HB-TRX after, Lee is with LIYIMIN, 86,0755,00,000,000 4 groups of information input equipments.Certain year one day, Lee is in danger stranded to the Xinjiang self-driving travel, and Lee triggers the HB-TRX that carries, and terminal is sent one group of CW Morse newspaper in frequency F1, and then message is as follows:
SOS?SOS?SOS?DE?HBS?LIYIMIN?86?0755?00000000?SOS?E?86/18/58.7?N42/44/13.4?SOS。
Consideration for fear of conflict, the radio formula is called for help terminal before sending distress call, should will launch whether the monitoring space is just having strong signal emission on the frequency earlier, these signals might become the undesired signal of signal to be transmitted, and according to snoop results or strong send out or evade or wait in line and transmit, cause midair collision to avoid contiguous a plurality of terminals to launch simultaneously.
In addition, this terminal can also be listened to the rescue progress on predetermined broadcasting station short frequency.
Describe in detail below and keep several implementations of listening platform 2 in the present embodiment.
In theory, all amateurish short-wave receivers are no matter its index height, be that own product or commercial product all can serve as and keep a tin platform.Simultaneously, distress call has been contained each distance that sky wave, earthwave, direct wave can reach, thus present embodiment do not repel go up in all senses with any orientation on keep and listen a platform.
Because the user terminal 1 in the present embodiment adopts CW Morse message transmission distress signal, therefore keep and listen platform 2 " super arrowband " characteristic at CW Morse newspaper, design several low costs and efficiently utilized the reception programme of frequency spectrum resource, and adopt the method that increases the reception redundance to improve the system communication success ratio, improve receiving sensitivity greatly.
During specific implementation, described keeping listens platform 2 can adopt the distress call receiving trap that designs at native system specially provided by the invention, also can be radio amateur (Radio Amateur, be commonly called as HAM) short-wave receiver that uses, what described short-wave receiver adopted is monolateral band (Single SideBand, SSB) receiver.Keep listen a platform 2 to receive distress signal after, behind recorder time and data content, the brief analysis geographical location information, the clientage's contact method Advise By Wire clientage according in the data can also issue distress signals on the website, so that allow more people see.
Be example with the interior transmission situation of " first jumps " distance below, concrete path loss and the receiving sensitivity of setting forth when using the SSB receiver.
Shortwave can be divided into sky wave, earthwave and direct wave according to circulation way, and present embodiment based on the sky wavelength apart from propagation, it is auxilliary propagating with earthwave, direct wave low coverage.According to the propagation empirical value of shortwave, shortwave ionospheric reflection first hop distance can reach 1000-3750Km, the about 100-120dB of path loss, the whenever continuous later on once about 7dB of loss that jumps.The SSB receiver sensitivity of the employed common short wave receiver of HAM generally can reach 0.16uV at present, promptly-and 123dBm (10dB S/N, bandwidth 2.4KHz/-6dB).Value rule of thumb, CW can work being lower than under the SSB mode 3dB limiting case, so CW sensitivity (7dBS/N) can reach-123dBm-3dB=-126dBm; In the present embodiment, the SSB receiver should use " arrowband " to receive as much as possible, in order to make receiver be more suitable for receiving the consideration of deciding the frequency narrow band signal, second intermediate-frequency bandwidth of SSB receiver can be changed into 500Hz (500Hz/-6dB), then its sensitivity will improve about 10log (2400/500)=7dB, reach-133dBm; The emissive power of supposing user terminal 1 is 33dBm (2W), what transceiver terminal used that half-wave is about 10m tiltedly draws antenna fast, the SSB receiver can use the Yagi antenna of conventional half-wave dipole antenna (Diople) or high-gain, dual-mode antenna gain total is got minimum 3dB, the first jumping path loss is got 120dB, the signal intensity that then arrives SSB receiver port is 33dBm+3dB-120dB=-84dBm, the high 49dB of ratio-133dBm, promptly there is the reception redundance of 49dB in this system.
Propagation path loss when describing the distress call receiving trap that adopts this system-specific in detail below.
With reference to figure 3, this figure is the circuit theory diagrams of distress call receiving trap first embodiment provided by the invention; As shown in the figure, for increasing the inhibition of undesired signal and reducing the noise of each link, a preselector F0 and an intermediate-frequency filter IF1 adopt the arrowband, and two intermediate-frequency filter IF2A adopt 25Hz or the super arrowband of 50Hz, a local oscillator F
L1Adopt the VCXO VCXO (VCXO ± 750Hz),, append one-level narrow band filter IF2B that makes an uproar very low mutually at its output terminal for suppressing to put in the high-gain two broadband noise of output.
If the reception bandwidth of described distress call receiving trap is 25Hz, total noise of centrifuge coefficient NF is 8dB, and peak response is 10log (KT when can be regarded as to such an extent that satisfy 7dB S/N.BF)+7dB＝10logKT。+10logB+NF+7dB＝-174dBm+14dB+8dB+7dB＝-145dBm。This moment, the CW power of 3W was equivalent to common SSB emission 475W, and therefore, the distress call receiving trap has the reception redundance of 61dB.
If transmitting-receiving is all used ± 10ppm common crystals working frequency benchmark, if Fo=14MHz, then worst transmitting-receiving frequency mismatch can reach 10*14 (frequency difference of making a start)+10*24.7 (fL1 frequency difference)+10*10.245 (fL2 frequency difference)+10*0.455 (wave filter frequency difference) ≈ ± 495Hz, 25Hz receiving belt wide region " covers incessantly " signal most probably in the practicality head and shoulders above.
Therefore, present embodiment has designed a kind of " scanning cladding process ".With reference to figure 4, this figure is the schematic diagram of scanning cladding process in the present embodiment; As shown in the figure, normally keeping when listening, is that center, 25Hz are stepping with this machine nominal frequency, carries out ± 20step scan round, finds to stop scanning and receive described signal in this point behind the signal.The defective of this scanning cladding process is to miss the part message because of scanning.Yet, user terminal 1 every the wheel with three messages of 20wpm repeat its transmission, when accounting for about 50 seconds at every turn, supposed every scanning ± 20step 4 seconds consuming time, therefore, the worst situation is to lose first in the message of emission two " SOS SOS " and the core message content still is very complete, adds down repeat its transmission twice, can guarantee that then receiving trap intactly receives whole messages.
With reference to figure 5, this figure is the circuit theory diagrams of distress call receiving trap second embodiment provided by the invention; Be the consideration of indexs such as raising mirror image inhibition, the distress call receiving trap in the present embodiment adopts high intermediate frequency received signal, but if still employing ± 10ppm is steady frequently, the sending and receiving end frequency error will reach the degree of can't stand.Therefore, on the basis of above-mentioned first embodiment, present embodiment has increased a time service type GPS module, i.e. GPS MCU shown in the figure and GPS 1PPS control, and this module functions is frequency stabilization, GPS 1PPS precision is ± 1us one local oscillator F
L1Middle PLL reference frequency crystal oscillator and two local oscillator F
L2All adopt VCXO, these two VCXO are carried out adjustment, can make receiver obtain high frequency accuracy with the 1PPS signal.With reference to figure 6, this figure is the adjustment schematic diagram of present embodiment call signal receiving trap; As shown in the figure, establishing the PLL benchmark is the 10MHz VCXO, and 1us numeration error is 10, and it is voltage-controlled that it is carried out counting and feeding back in continuous 10 seconds, then the precision of VCXO can be controlled at ± 10/10*10M=± 0.1ppm; In like manner, two local oscillator F
L2Precision also can be controlled in ± 0.1ppm.The benefit of present embodiment is to greatly reduce worst transmitting-receiving both-end frequency mismatch, is 10*14 (frequency difference of making a start)+0.1*78.455 (f
L1Frequency difference)+0.1*64 (f
L2Frequency difference)+and 10*0.455 (2 median filter IF2 frequency difference) ≈ ± 158Hz, reach the effect that quicker lock for sweep receives.
During specific implementation, listen platform by non-profit-making the keeping that particular organization is provided with, can adopt aforesaid distress call receiving trap, the advantage of this device is to be exclusively used in the distress signal that receives on the described user terminal 1 emission frequency, sensitivity is very high, and described particular organization can be user terminal manufacturer or group of public and social interest, also can be common fan with good conditionsi.
During specific implementation,, antenna feeder should be erected at the optimum position in order to optimize the consideration of received signal.
For the consideration of more optimizing, can also add low bandpass filter BPF of damage in arrowband and LNA LNA at SSB receiver or distress call receiving trap front end, further improve performances such as its signal to noise ratio (S/N ratio) and antiblocking.
Describe the clientage in the present embodiment below in detail.
Clientage 3 can be relatives, bosom friend, guardian or the specific relief group of captive.Its telephone number is imported in advance by the user.When clientage 3 receive keep the Advise By Wire of listening platform 2 and affirmation situation true after, promptly initiate rescue action, as rescuing etc. with captive region 110 association request.Simultaneously, for captive being felt at ease and in time understanding the rescue progress, clientage 3 can dial the hotline that shortwave broadcasting radio station 4 is provided with, ask its rescue progress of described shortwave broadcasting radio station 4 broadcasting, receive after this request in described shortwave broadcasting radio station 4, in specific frequency broadcasting, radio formula transceiver terminal 1 can utilize radio receiver module 11 to listen on this frequency.Described shortwave broadcasting radio station 4 can be nationwide shortwave Chinese broadcasting station, as Chinese international broadcasting CRI etc.
The above is a preferred implementation of the present invention; should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the principle of the invention; can also make some improvements and modifications, these improvements and modifications also are considered as protection scope of the present invention.
Claims (11)
1. a wireless wide-area system for calling for help is characterized in that, comprising:
User terminal is used to send the shortwave continuous wave distress call of the calling for help person's information that carries, clientage's information and this user terminal geographical location information;
Be distributed in keeping of various places and listen platform, be used to receive the distress call of described user terminal, and described distress call notified the clientage of appointment in the distress call.
2. wireless wide-area system for calling for help as claimed in claim 1 is characterized in that, described distress call transmits with the Morse code form.
3. wireless wide-area system for calling for help as claimed in claim 1 or 2 is characterized in that, this system also comprises:
The shortwave broadcasting radio station is used for clientage's rescue information is sent to the user terminal of calling for help the people with the form of broadcasting.
4. a radio formula is called for help terminal, comprises the short wave receiver that is used to receive the signal of launching in the shortwave broadcasting radio station, it is characterized in that, also includes:
Geographical location information obtains device, is used for obtaining from GPS the geographical location information of this calling for help terminal seat;
The distress call emitter is used to launch the shortwave continuous wave distress call that adopts the Morse code form, and described distress call comprises calling for help person's information, clientage's information and geographical location information.
5. radio formula as claimed in claim 4 is called for help terminal, it is characterized in that, the signal transmission frequency of described distress call emitter is shortwave ham radio emission frequency.
6. radio formula as claimed in claim 5 is called for help terminal, it is characterized in that described distress call emitter is at least twice the emitting times of each distress call.
7. radio formula as claimed in claim 6 is called for help terminal, it is characterized in that the emissive power of described distress call emitter is a miniwatt.
8. call for help terminal as each described radio formula among the claim 5-7, it is characterized in that, before the distress call emitter sends distress call, on described emission frequency, monitor whether there is undesired signal, and launch described distress signal according to snoop results.
9. distress call receiving trap, be used to receive the shortwave continuous wave signal, comprise the multiple filter and the multistage local oscillator that are set in turn in the circuit, it is characterized in that described multistage frequency wave filter is that narrow band filter or ultra-narrow bandwidth filter, a described local oscillator are VCXO and also are provided with a narrow band filter at its output terminal.
10. distress call receiving trap as claimed in claim 9 is characterized in that, this device adopts the scan round mode to intercept locking signal.
11. as claim 9 or 10 described distress call receiving traps, it is characterized in that, on local vibration source, also be connected with time service type GPS module.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2008100652052A CN101226675A (en) | 2008-01-28 | 2008-01-28 | Wireless wide-area system for calling for help |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2008100652052A CN101226675A (en) | 2008-01-28 | 2008-01-28 | Wireless wide-area system for calling for help |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101226675A true CN101226675A (en) | 2008-07-23 |
Family
ID=39858647
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2008100652052A Pending CN101226675A (en) | 2008-01-28 | 2008-01-28 | Wireless wide-area system for calling for help |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101226675A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101808426A (en) * | 2010-03-19 | 2010-08-18 | 华为终端有限公司 | Radio communication method and terminal |
| CN102075275A (en) * | 2010-12-14 | 2011-05-25 | 北京西军电信息科技有限公司 | Control system for transmitting and receiving urgent message |
| CN103338446A (en) * | 2013-07-02 | 2013-10-02 | 惠州Tcl移动通信有限公司 | Method, device and mobile terminal for intelligently protecting safety of user |
| CN106792495A (en) * | 2015-11-25 | 2017-05-31 | 西安中兴新软件有限责任公司 | A kind of information transferring method and mobile terminal |
-
2008
- 2008-01-28 CN CNA2008100652052A patent/CN101226675A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101808426A (en) * | 2010-03-19 | 2010-08-18 | 华为终端有限公司 | Radio communication method and terminal |
| CN102075275A (en) * | 2010-12-14 | 2011-05-25 | 北京西军电信息科技有限公司 | Control system for transmitting and receiving urgent message |
| CN103338446A (en) * | 2013-07-02 | 2013-10-02 | 惠州Tcl移动通信有限公司 | Method, device and mobile terminal for intelligently protecting safety of user |
| CN103338446B (en) * | 2013-07-02 | 2018-03-20 | 惠州Tcl移动通信有限公司 | A kind of method, device and mobile terminal of intelligent protection user security |
| CN106792495A (en) * | 2015-11-25 | 2017-05-31 | 西安中兴新软件有限责任公司 | A kind of information transferring method and mobile terminal |
| WO2017088297A1 (en) * | 2015-11-25 | 2017-06-01 | 西安中兴新软件有限责任公司 | Information transmission method, mobile terminal and computer-readable storage medium |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5343493A (en) | Personal assistance system and method for use with a cellular communication system | |
| US20060141929A1 (en) | Cellular communication system | |
| US20030129977A1 (en) | Emergency rescue aid | |
| GB2560469A (en) | MIMO satellite service terminal | |
| DE60117007D1 (en) | DRAWING DEVICE AND COMMUNICATION SYSTEM | |
| KR20030036211A (en) | Mobile network for remote service areas using mobile stations | |
| GB2179823A (en) | Communications system | |
| CN109246818B (en) | Paging method and device | |
| CN101226675A (en) | Wireless wide-area system for calling for help | |
| US20240129072A1 (en) | Method for determing drx activation time and terminal device | |
| ECSP055721A (en) | WIRELESS WIRELESS PHONE CIRCUIT | |
| CN209419635U (en) | A kind of high reliability emergency broadcase system of Promote in Multiple Channels | |
| CN202931333U (en) | Multifunctional emergency early warning information broadcasting receiver | |
| CN114142913B (en) | Method and beacon for enhancing reverse link message reception | |
| Chen et al. | A personal emergency communication service for smartphones using FM transmitters | |
| CN105824320A (en) | Aircraft emergency control device and control method thereof | |
| CN106657699A (en) | Satellite communication system for remote working area | |
| CN212229807U (en) | Ground base station based on mobile network communication and satellite positioning system | |
| CN202424965U (en) | Multimode interphone | |
| CN212305395U (en) | Device for amplifying and repeating L-band satellite telephone signal | |
| CN202587110U (en) | Handheld satellite phone indoor answer amplifier | |
| WO2002017657A3 (en) | Transportable self-contained communications unit comprising transmission equipment and antennas for reconnecting a disconnected cell site to a communications network | |
| WO2023000268A1 (en) | Method for acquiring time in non-terrestrial network, and terminal device and storage medium | |
| JP2003304583A (en) | Personal communication device having emergency mode | |
| KR20160090577A (en) | A Portable Lantern for rescuing distress |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C12 | Rejection of a patent application after its publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20080723 |