CN1156354A - Satellite communications system having user RF exposure monitoring and control - Google Patents
Satellite communications system having user RF exposure monitoring and control Download PDFInfo
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Abstract
Disclosed are a method for operating a communication system and the system. The method comprises following steps that a wireless connection of the system with a terminal of the user is established through a forward link and a return link; in the course of connection, the average transmit power density linked with a user terminal antenna is equal to or more than a preset threshold and an absolute threshold, in a preset time unit and corresponding to a terminal user; the connection is stopped before the average transmit power density is equal to or more than the threshold.
Description
The present invention relates generally to communication system, and be specifically related to satellite communication system that a plurality of user terminals carry out two-way wireless communication by gateway and at least one satellite and a terrestrial communications network in this satellite communication system.
Existing rule predetermining at the fixed time at interval within wireless terminal user can be by the RF energy emission total amount of (for example, within half an hour average) on the threshold power density of radiation.
A kind of technology of definite user's radiation is to monitor radiant power and the radiant power that surpasses thresholding is asked average in time in user terminal.If in designated time intervals, surpassed thresholding, this user terminal can not be operated, so that make the user leave the RF energy of emission.
Yet this method can cause user terminal to be modified or to process and make this disabler.Use the convenience of terminal though guaranteed user's total energy, the user may be exposed to potential harmful RF energy level.
In addition, one is processed to the user terminal operated on the admissible average power density of appointment, if thresholding was changed afterwards, and will be out-of-date.Therefore, in user terminal, provide this function that many shortcomings are arranged.
Primary and foremost purpose of the present invention provides the RF energy that a telemonitoring user is exposed, and stops the method and system that connects or call out when user's radiation will be above a predetermined thresholding.
Another object of the present invention provides the method and system of this user terminal of denial of service when identifying a user terminal and will cause a user to be exposed to RF energy emission above appointed threshold.
By a kind of by system gateway (GW) from the closed power control information determine the method for the antenna power density of a user terminal overcome aforementioned and other problem and realized purpose of the present invention.GW also keeps a power density to surpass the duration record of appointed threshold.The average transmit power density that GW determines to be associated with user terminal antenna equals or exceeds at least one predetermined thresholding in whether will be during an official hour, or surpasses an absolute thresholding.If call out connection if GW determines to keep one, just might surpass thresholding, GW just stopped connecting before user terminal average transmit power density level equals or exceeds predetermined or absolute thresholding level.
If the radiation of threshold amount obviously will take place to surpass, GW preferably notifies the current connection of user or calls out and will be terminated by a sound or a visual indicating device.Thereafter, suppose that the user is still connecting, GW automatically stops this connection, and refusal serves this user once more, till time enough is not when radiation thresholding in back will can be exceeded at once in the past.The calling (for example, urgent call) of predefined type is carried out in permission at intercourse.
Also carry out the power density function for monitoring also within the scope of the invention at user terminal.In this case, information can be transmitted into GW by return link, and GW can use favorable or some other the technology of majority before stop connecting.In this case, the power density of carrying out in GW is determined to have precedence over and is carried out in user terminal, makes the power density function for monitoring invalid wittingly or by mistake to avoid user terminal.Function for monitoring also can all or part ofly carry out in satellite.
This invention is preferably but be not among the embodiment that only limits to, relate to one comprise at least one earth-orbiting satellite, at least one is positioned at the satellite communication system of the user terminal and the gateway that at least one is positioned at land on land.Gateway comprises that circuit and analog are used for transmitting two-way wireless communication by at least one satellite between a terrestrial communications systems and at least one user terminal and connect.Whether the RF radiation that at least one at least one gateway, at least one satellite and at least one user terminal are included in the user who determines to be associated with terminal at least one connection procedure will equal or exceed the circuit or the analog of thresholding.Also provide the mechanism of control wireless connections to equal or exceed thresholding with the RF radiation of avoiding the user.
The above-mentioned characteristic with other of the present invention can become apparent in reading detailed description of the present invention in conjunction with the accompanying drawings, wherein:
Fig. 1 is the block diagram of a satellite communication system, and this system constructs and running according to currently preferred embodiments of this invention;
Fig. 2 is the block diagram of a gateway among Fig. 1;
Fig. 3 A is the block diagram of the communication Payload of a satellite among Fig. 1;
Fig. 3 B illustrates the part of a beam patterns related with a satellite among Fig. 1;
Fig. 4 is a block diagram of describing the ground installation of supporting satellite telemetry and controlled function;
Fig. 5 is the block diagram of the CDMA subsystem of Fig. 2;
Fig. 6 is a block diagram of at length showing the satellite communication system of notion of the present invention; And
Fig. 7 is the chart of explanation in the definite demonstration user terminal transmitter power density of gateway.
Fig. 1 illustrates a currently preferred embodiment that is applicable to the satellite communication system 10 of currently preferred embodiment of the present invention.Before describing the present invention in detail, at first communication system 10 to be described so that can understand the present invention more up hill and dale.
Communication system 10 can be subdivided into a plurality of parts 1,2,3 and 4 conceptive.Part 1 is called space segment here, and part 2 is called User Part, and part 3 is called ground (land) part, and part 4 is called the telephone system infrastructure portion.
In currently preferred embodiment of the present invention, for example on one 1414 kilometers Low Earth Orbit (LEO), one has 48 satellites.Satellite 12 is dispensed on eight orbital planes, each plane (Walker constellation) six satellites that distribute equidistantly.Orbital plane is 52 degree with respect to the inclination angle in equator, and every satellite was finished an orbital motion in per 114 minutes.This method provides a kind of approximate whole world to cover, preferably, in given time arbitrarily, about 70 ° in south latitude and approximately a specific user between 70 ° of the north latitude can see at least two stars.Like this, the user can pass through one or more gateways (GW) 18 and one or more satellite 12, also may use the part of telephony infrastructure part 4, to or almost any point of the earth surface that covers from gateway (GW) 18 to or other some communication (passing through PSTN) from the earth surface.
An embodiment that is fit to that wherein can find the communication system of notion use of the present invention is only represented in the description that is noted that aforesaid and system thereupon 10 here.That is to say that the specific details of communication system can not be read or explain under the limited practice situation of the present invention.
Continue descriptive system 10 now, a soft transfer (switching) is carried out between satellite 12, also carry out between each in 16 spot beams of each satellite (Fig. 3 B) emission simultaneously, provide uninterrupted communication by spread-spectrum (SS), code division multiple access (CDMA) technology.Though also can use other spread-spectrum and CDMA technology and agreement, the preferred SS-CDMA technology type of the present invention is similar to the TIA/EIA tentative standard, " mobile radio station-base station compatible standard that is used for double mode broadband spread-spectrum cellular system " TIA/EIA/IS-95, in July, 1993.
Low Earth Orbit allows 12 communications via satellite of low-power user terminal 13 fixing or that move, the function of each such satellite is " bend pipe " repeater in presently preferred embodiment of the present invention, be used to receive communication traffic signal (as language and/or data) from user terminal 13 or gateway 18, the communication traffic signal that receives is transformed to another frequency range, and retransmit the signal of this conversion.That is to say, signal processing on the star of the communication traffic signal that does not receive, satellite 12 does not have any intelligence aspect the transmission of reception and emission communication traffic signal simultaneously.
In addition, between satellite 12, there are not DCL or link.That is to say that 12 on each satellite is from being positioned at User Part 2 or being positioned at the transmitter received signal of above ground portion 3, and only transmit to the receiver that is positioned at User Part 2 or is positioned at above ground portion 3.
But notice fixed radio telephone 14a user tropism antenna.This is an advantage, because it can reduce the interference that is brought by must the increasing of number of users of one or more satellite 12 services simultaneously.
It is also noted that user 13 can be a Dualpurpose installation, also comprises the circuit of communicating by letter with terrestrial cellular system with conventional method.
Again with reference to figure 3A, user terminal 13 may be capable of operating upon full-duplex mode and pass through respectively, such as, L-band RF link (up link or return link 17b) and S-band RF link (down link or forward link 17a) are communicated by letter with 12b via returning with forward direction satellite repeater 12a respectively.Return L-band RF link 17b and can operate at 1.61GHz in the frequency range of 1.625GHz, bandwidth is 16.5MHz, and modulates according to preferred spread spectrum technique with grouping audio digital signals and/or data-signal.Forward direction S-band RF link 17a can operate at 2.485GHz in the frequency range of 2.5GHz, and bandwidth is 16.5MHz.Forward direction RF link 17a also can modulate according to preferred spread spectrum technique at gateway 18 usefulness grouping audio digital signals and/or data-signal.
The 16.5MHz bandwidth of forward link is divided into 13 channels, and each channel can be distributed to as many as, such as, 128 users.Return link can have different bandwidth, and given user terminal 13 can distribute one with forward link on similar and different channel.Yet when return link running when diversity reception pattern (receiving) from two or more satellites 12, giving user's forward direction for each satellite distribution is identical with return link RF channel.
Above ground portion 3 comprises at least one but generally is a plurality of gateways 18, this gateway 18 passes through, such as, full duplex C-band RF link 19 (forward link 19a (to satellite), return link 19b (from satellite)) communicates by letter with satellite 12, this link is usually operated at the above frequency range of 3GHz, preferably at C-band.C-band RF link bidirectional ground transport communication is presented link, and is transferred to the satellite order of satellite and from the telemetry intelligence (TELINT) of satellite.Forward feeder link 19a can operate at 5GHz to the wave band of 5.25GHz, and reverse feeding link 19b can operate at 6.875GHz to the wave band of 7.075GHz.
Satellite feed link antennas 12g and 12h preferably it seems the wide cover antenna of opening maximum earth overlay area from LEO satellite 12.In the preferred embodiment of current communication system 10, it approximately is 110 ° from the subtended angle (supposing that to the elevation angle of earth surface be 10 °) of a given LEO satellite 12.This has just obtained a diameter approximately is 3600 miles cover tape.
L-band is the multi-beam antenna that covering is provided in relevant coverage, land with the S-band antenna.L-band and S-band antenna 12d and 12c, preferably consistent respectively with another, shown in Fig. 3 B.Just, the wave beam that transmits and receives from aircraft covers same zone on the earth surface, although this characteristic is not very crucial for the running of system 10.
For example, several thousand full-duplex communications can produce by a given satellite 12.According to a characteristic of system 10, two or more satellite 12 each can the same communication of transmission between a given user terminal 13 and gateway 18.This operating mode, as described in detail later, the diversity that is provided on the respective receiver merges, and realizes the raising of anti-fading property, and helps implementing soft switching process.
Point out that all frequencies of Miao Shuing, bandwidth and similar thing are only represented a specific system here.Other frequency and frequency range also can be used under the situation that does not change the principle of being discussed.Only as an example, presenting link and can use C-band (approximately 3GHz is to about 7GHz) frequency in addition between gateway and the satellite, for example Ku wave band (approximately 10GHz is to about 15GHz) or Ka wave band (approximately more than the 15GHz).
In this respect also can be with reference to U.S patent No. No.5,422,647, E.Hirshfield and C.A.Tsao, be entitled as " Mobile Communications Satellite Payload ", this article has disclosed a kind of communication satellite Payload that uses when being suitable for lecturing notion of the present invention.
Telephony infrastructure part 4 comprises existing telephone system and comprises Public Land Mobile Nerwork (PLMN) gateway 20, for example regional public telephone network of local telephone exchange one (RPTN) 22 or other local telephony service supplier, national trunk network 24, international networks 26, private network 28 and other RPTNs30.It may be to provide two-way voice and/or data communication between the user terminal of dedicated network that communication system 10 is used for various at public switched telephone network (PSTN) phone 32 of User Part 2 and telephony infrastructure part 4 and non-pstn telephone 32 or other.
As the part of above ground portion 3, (and in Fig. 4) also represented satellite running (SOCC) 36 of control centre and ground running control centre (GOCC) 38 among Fig. 1.For TCUs18a, SOCC36 and the interconnection between the GOCC38 of gateway 18 and above ground portion 3 provides a communication port, this passage has comprised a ground data network (GDN) 39 (see figure 2)s.This part of communication system 10 provides overall system control function.
Fig. 2 has represented in the gateway 18 in more detail.Each gateway 18 comprises nearly four dual polarization RFC wave band subsystems, and each subsystem comprises a teledish 40, antenna driver 42 and pedestal 42a, low-noise receiver 44 and high power amplifier 46.All these parts also can be in the antenna cover structure so that environmental protection to be provided.
Gateway 18 also comprises low-converter 48 and upconverter 50, handles the RF carrier signal that receives and launch respectively.Low-converter 48 and upconverter 50 are connected to CDMA subsystem 52, and the latter is connected to public switched telephone network (PSTN) by PSTN interface 54 again.As an option, PSTN can be by using the link bypass of satellite to satellite.
CDMA subsystem 52 comprises that a signal adds up/crosspoint 52a, a gateway transceiver subsystem (GTS) 52b, GTS controller 52c, CDMA interconnects subsystems (CIS) 52d and a selector array subsystem (SBS) 52e.CDMA subsystem 52 is worked by base station manager (BSM) 52f control and with a kind of mode that is similar to a CDMA compatibility (for example, IS-95 compatibility) base station.CDMA subsystem 52 also comprises desired frequency synthesizer 52g and a global positioning system (GPS) receiver 52h.
Gateway 18 provides the fixed signaling of SS-7ISDN to CCP54b.In gateway one side of this interface, from then on CCP54b and CIS52d interface also arrive CDMA subsystem 52.CCP54b is that system space interface (AI) provides protocol conversion function, is similar to the tentative standard that IS-95 is a cdma communication.
Piece 54c and 54d generally provide the interface between gateway 18 and the outside cellular radio network, this telephone network with, for example, IS-41 (North America standard, AMPS) or GSM (European standard, MAP) cellular system is compatible mutually, and particularly at the user who handles ramber-beyond their main system, send calling-designation method.The subscriber terminal authority of gateway 18 back-up system 10/AMPS phones and the 10/GSM of system phone.In the coverage that does not have the existing infrastructure of telecommunication, HLR can be added in the gateway 18 and with the SS-7 signaling interface.
The user that (ramber) makes a call outside the general coverage of user if authorized, just can be held by system 10.Since can find the ramber in any environment, the user just can use identical terminal equipment under the sun making a call, and necessary protocol conversion is carried out pellucidly by gateway 18.When not needing to change, for example from GSM to AMPS, protocol interface 54d can bypass.
Within concept and range of the present invention, special, a general interface of honeycomb gateway 20 is provided, be additional to or replace with " A " interface of conventional GSM mobile switching centre appointment and arrive the interface of manufacturer's formulation of IS-41 mobile switching centre.Provide one directly to the interface of PSTN, as indicated in the signalling channel that is designated as PSTN-INT among Fig. 1, also within the scope of the invention.
Overall gateway control is provided by gateway controller 56, and the latter comprises an interface and the interface to service supplier control centre (SPCC) 60 to above-mentioned ground data net (GDN) 39.Gateway controller 56 is generally by BSM 52f be incorporated into each RF controller 43 and gateway 18 interconnection in the antenna 40.Gateway controller 56 is also connected to a database 62, for example customer data base, satellite almanac data, etc., and be connected to one and allow the business personnel to visit the I/O unit 64 of gateway controller 56.GDN39 also with remote measurement and order (T﹠amp; C) unit 66 (Fig. 1 and Fig. 4) bidirectional interface.
With reference to figure 4, the function of GOCC38 is the utilization of plan and 18 pairs of satellites of control gateway, and coordinates this utilization with SOCC36.In general, the GOCC38 analytic trend produces business plan, distribute satellite 12 and system resource (for example, but being not limited thereto power and channel allocation), monitor the performance of whole system 10, and send to gateway 18 by GDN39 in real time or in advance and utilize indication.
SOCC36 is used for safeguarding and monitoring orbital motion, repeater satellite use information to gateway so that be input to GOCC38 by GDN39, monitor the whole functional of each satellite 12, the state that comprises satellite battery, for the RF signalling channel in the satellite 12 is provided with gain, guarantee the orientation of best satellite with respect to earth surface, and some other function.
As mentioned above, the function of each gateway 18 is for signaling, voice and/or data communication are connected to PSTN with a given user, and also is used for chargeing in order to produce data by database 62 (Fig. 2).Selected gateway 18 comprises a remote measurement and command unit (TCU) 18a, is used to receive satellite 12 and says the word to satellite 12 by the telemetry of return link 19b emission and by forward link 19a.GDN39 is used for gateway 18, GOCC38 and SOCC36 are interconnected.
In general, every satellite 12 of LEO constellation be used for relaying from the information of gateway 18 to user (C-band forward link 19a is to S-band forward link 17a), and relaying from user's information to gateway 18 (L-band return link 17b is to C-band return link 19b).This information comprises the synchronous and paging channel of SS-CDMA, and power control signal.Different CDMA pilot channels also can be used for monitoring the interference on the forward link.Satellite ephemeris more new data also from gateway 18, via satellite 12, be transferred to each user terminal 13.Satellite 12 also be used for relaying from the signaling information of user terminal 13 to gateway 18, comprise connect people's request, power changes request and register requirement.Satellite 12 is trunking traffic signal between user and gateway 18 also, and provides safety assurance for alleviating undelegated use.
Be in operation, satellite 12 sends the aircraft telemetry, comprises the measurement of satellite transit state.From the telemetry data stream of satellite, present link 19 from the order of SOCC36 and communication and all share C-band antenna 12g and 12h.Comprise the gateway 18 of a TCU18a for those, the satellite telemetering data of reception can be forwarded to SOCC36 immediately, and perhaps telemetry can be stored earlier and be forwarded to SOCC36 then after a period of time, generally will be through the request of SOCC.No matter send immediately or storage forwarding then, telemetry all will send as grouping information by GDN39, and each grouping information comprises a single less telemetry frame.If more than one SOCC36 provides the satellite support, telemetry will be routed to all SOCC.SOCC36 and GOCC38 have several interface functions.An interface function is a track location information, here SOCC36 to GOCC38 orbit information is provided in case each gateway 18 can accurately follow the tracks of may be in this gateway visual field four satellites.These data comprise tables of data, enough allow gateway 18 to use known their satellite contacts list of algorithm development.SOCC36 does not need to understand gateway tracking plan.TCU18a searches down link remote measurement wave band, and before propagating order, discerns the satellite of each day line following uniquely.
Another interface function is a satellite state information, is reported to GOCC38 by SOCC36.Satellite state information comprises availability, battery status and the orbit information of satellite/transponder, and generally in conjunction with any satellite relative restrictions, and all or part of that prevents to use satellite 12 is used for communication.
An importance of system 10 is to use SS-CDMA, and the diversity that is combined in gateway receiver and user terminal receiver place merges.Diversity is associated with and helps alleviate fading effect, and this is to produce from many different passage lengths arrival user terminals 13 of a plurality of passings of satelline or the signal of gateway 18.Rake receiver in user terminal 13 or the gateway 18 is used to receive and merges the signal from multiple source.For example, user terminal 13 or gateway 18 provide the diversity of forward link signal or return link signal to merge, and these signals receive or a plurality of beam transmission of 12 via satellite from a plurality of wave beams of satellite 12 simultaneously.
In this respect, the U.S. patent No. No.5 of the Stephen A.Ames of promulgation on August 3rd, 1993,233,626, the disclosure that is entitled as " Repeater Diversity Spread Spectrum Communication System ", all as a reference incorporated here.
Performance in continuous diversity reception pattern is better than receiving by a satellite relay performance of a signal, and particularly in communication, there is not an interruption, thereby because because the covering or block when having harmful effect to received signal of tree or other barriers, a link will break.
A plurality of directive antennas 40 of a given gateway 18 can merge with the diversity that is supported in the user terminal 13 by the different beams emission forward link signal (gateway is to user terminal) of one or more satellites 12.The omnidirectional antenna 13a of user terminal 13 can " see " all satellite beams emissions by user terminal 13.
Each gateway 18 is supported the transmitter power controlled function at slow fading, and also supports block interleaving at the factor that causes rapid fading.Power is controlled on forward direction and the reverse link and all carries out.The response time of control function of power adjust to be fit to 30 milliseconds satellite back and forth distance postpone this worst condition.
Block interleaving (53d of Fig. 5,53e, 53f) is operated on the length of a piece, and this length is relevant with the packet frames of vocoder 53g.Therefore the length that best weaving length compromise selection is long improved error correction, is cost to increase whole end-to-end delay still.Preferred maximum end-to-end delay is 150 milliseconds or still less.This delay comprises all delays of delay that the received signal of carrying out owing to diversity combiner is aimed at the delay of the delay that causes, block interleaver 53d-53f and formed the Viterbi decoder (not showing) of CDMA subsystem 52 parts.
Fig. 5 is the block diagram of the forward link modulating part of CDMA subsystem 52 among Fig. 2.Merge a frequency sensitive upconverter of the output feedback people 53b of module 53a, 53b follows feed-in merging and Switching Module 52a.Remote measurement and control (T﹠amp; C) also input module 52a of information.
Unmodulated direct sequence SS pilot channel produces complete 0 Walsh sign indicating number with required bit rate.This data flow merges with the short PN code that is used for from different gateways 18 and different satellite 12 differentiation signals.If used pilot channel, pilot channel just adds with short code mould 2, and QPSK or BPSK expand to CDMA FD RF channel width then.Provide following several different puppet (PN) sign indicating number skew: (a) allow the PN sign indicating number skew of a gateway 18 of user terminal 13 unique identifications; (b) allow the PN sign indicating number of a satellite 12 of user terminal 13 unique identifications to be offset; And (c) allow user terminal 13 unique identifications given PN sign indicating number skew of one from 16 wave beams of satellite 12 emissions.Specified different time/phase deviation from the Pilot PN sign indicating number of different satellite 12 with respect to same pilot tone seed PN sign indicating number.
If used pilot channel, each pilot channel of gateway 18 emission can be with higher or be lower than the power level of other signals.Pilot channel makes user terminal 13 can catch the timing of Forward CDMA Channel, and the phase reference of coherent demodulation is provided, and when the signal strength signal intensity comparison starts handover with judgement the mechanism of carrying out is provided.But might not use pilot channel, other technologies also can be used for this purpose.
Synchronizing channel produces the data flow that comprises following message: (a) date; (b) emission gateway identification; (c) satellite ephemeris; And (d) paging channel of appointment.Synchrodata offers convolution coder 53h and carries out convolutional encoding, and block interleaving is with anti-rapid fading then.The data flow that produces adds with Walsh sign indicating number mould 2 synchronously, and QPSK or BPSK expand to CDMA FD RF channel width.
Paging channel offers convolution coder 53i and carries out convolutional encoding, block interleaving then.Data flow that produces and the output of long code generator 53j merge.Long PN sign indicating number is used to distinguish the frequency range of different user terminal 13.Paging channel and long code mould two adductions offer symbol and cover device, and signal of Chan Shenging and Walsh sign indicating number mould two add there.The signal that produces expands to CDMA FD RF channel width with QPSK or BPSK then.
In general, the information of the following several types of paging channel transmission: (a) system parameter message; (b) connect people's parameter information; And (c) CDMA Channel list information.
The parameter that system parameter message comprises configuration, the registration parameter of paging channel and helps to catch.Connect people's parameter packets of information and draw together the configuration and the access channel data rate of access channel.If the CDMA Channel list information has used, then transmit relevant pilot tone identification and Walsh sign indicating number and distribute.
Vocoder 53k is the service-data oriented stream of PCM with speech coding.Service-data oriented stream offers convolution coder 531, carries out convolutional encoding there, then block interleaving in module 53f.Data flow that produces and the output of user's long code module 53k merge.User's long code is used to distinguish different subscriber channels.The data flow that produces is carried out power control in multiplexer (MUX) 53m, add with Walsh sign indicating number mould two, and QPSK or BPSK expand to CDMA FD RF communication channel bandwidth then.
For access channel, the burst that connects on people's channel that 18 pairs of requests of gateway insert receives and decoding.Access channel information is presented as and then less relatively data of a long preamble.Preamble is the long PN sign indicating number of user terminal.Each user terminal 13 produces unique long PN sign indicating number by the unique time migration with respect to public PN generator polynomial.
After receiving the request of inserting, gateway 18 is gone up the information that sends in forward link paging channel (piece 53e, 53i, 53j), and the reception that inserts request is replied and distributed the Walsh sign indicating numbers to set up Traffic Channel for user terminal 13.Gateway 18 is also specified a frequency channels to user terminal 13.User terminal 13 and gateway 18 all switch to the channel appointed unit and bring into use Walsh (spread spectrum) sign indicating number of appointment to carry out duplex communication.
Return Traffic Channel in user terminal 13 by producing to carry out convolutional encoding from the numerical data of local data source or user terminal vocoder.Data are carried out block interleaving with predetermined interval then and are offered 128 system modulators and the data burst random device returns the correlation between the Traffic Channel with minimizing and disturbs.Data then with the PN sign indicating number of zero offset mutually adduction be transmitted into gateway 18 by one or more satellites 12.
Noted earlier is the description of communication system 10 presently preferred embodiments.What will do now is the description of presently preferred embodiment of the present invention.
With reference to figure 6, this figure has illustrated the block diagram of a simplification of the satellite communication system 10 among Fig. 1.User terminal 13 comprises that electric terminal sign (ETI) 13b discerns this terminal uniquely, comprises a terminal type (for example, vehicle-mounted, fix, hand, have only voice, voice/data, data, or the like).User 13 typically comprises a variable bit rate (1200,2400,4800,9600 baud) vocoder 13c, is used for the digital user language and the sound sign indicating number that will import is talked about and is converted to analog format.User terminal 13 also comprises a closed-loop transmitter control function of power 13d, can be similar to the regulation in the above-mentioned TIA/EIA tentative standard, i.e. " MobileStation-Base Station Compatibility Standard for Dual-Mode Wideband SpreadSpectrum Celluar System ", TIA/EIA/IS-95, in July, 1993.Antenna 13a is with user terminal 13 two-way one or more Low Earth Orbits (LEO) satellites 12 that are connected to.
The description of being done as earlier in respect of figures 3A, satellite 12 is bend pipe repeaters in this embodiment of the present invention, receive return link 17b and go up user's transmission from one in 16 wave beams, frequency inverted is identical, and subscriber signal is transmitted into a GW 18 on link 19b.Satellite 12 also receives from GW and presents link 19a, and frequency inverted is identical, and on forward link 17a by in 16 wave beams identical one signal is transmitted into user terminal.
GW18 is responsible for the power of user terminal transmitter in user terminal allocated channel and Walsh sign indicating number and the controlling call process.By detecting user terminal signal on return link, and adjust the transmitter power of user terminal with the power control bit that periodically sends on the forward link, the power of user terminal transmitter is controlled with the discrete mark increment of 1dB.This process generally is based on each vocoder frame and produces, perhaps in satellite communication system 10 presently preferred embodiments be per 20 milliseconds (per seconds 50 times) once.
As what point out above, because GW18 is with the power level of power control bit with frame rate continuous control user terminal, so the transmitter power level of user terminal 13 is always known to GW18.Initial user terminal power level is informed GW18 when connection is set up for the first time, and the adjustment of user terminal power level is all carried out from original levels subsequently.
According to the present invention, the power of GW18 monitoring user terminal omnidirectional antenna radiation (receiving) by return link, the power of conversion radiation is the power flow density (based on the certain distance d between antenna 13a and the user's body) at user's body place, the recording power current density surpasses the amount (being dash area) of predetermined threshold in the chart of Fig. 7, and the record amount is done time average.
A suitable expression formula of the power flow density (PFD) at judgement user's body place is as follows:
PFD＝EIRP/4πd2，
Here the effectively all square radiant power of EIRP representative of consumer health place direction (is unit with the milliwatt), and d be between radiation device (that is antenna 13a) and the user's body in centimetre distance.
Allow amount of radiation (for example, being 4mw/cm2 at distance d place) if average overall power density has reached the maximum of regulation, GW18 just sends the embedded controller 13e of an information to user terminal 13 on the forward link.This information that response receives, controller 13e shows an information to the user on terminal display 13f, shown information points out that ongoing calling will stop soon.Perhaps, give audible warning tones of user.The time that provides display message and/or sound preferably can allow the user to finish calling before calling is terminated.When soon surpassing maximum permission amount of radiation, if user terminal 13 still is in the connection, GW18 stops this connection automatically.
In general, GW18 determines whether will equal or exceed at least one predetermined thresholding, perhaps an absolute thresholding in the average transmit power density relevant with the antenna 13a of user terminal 13 is during a stipulated time.Connect when keeping if call out, GW18 determines to surpass possibly thresholding, and GW18 just stopped this connection before user terminal average transmit power density level equals or exceeds predetermined or absolute thresholding.
When terminal during near thresholding, GW18 reduces so that the time that terminal 13 is disconnected before connecting is long as far as possible the transmitting power of user terminal 13, and this also within the scope of the invention.Diversity level (that is the number of satellite 12) also can change so that keep enough return link quality in this respect.
Further according to the present invention, if user terminal 13 attempts reconnecting system 10 in the predetermined time period after stopping, the GW18 refusal connects this user terminal 13.After certain hour, user terminal 13 is allowed to reconnect, because the maximum radiation limitations (for example, half an hour) after a period of time that allows is designated.
Gateway controller 56 (Fig. 2) is that each user terminal 13 of gateway 18 management is determined and accumulation user radiation information.Radiation information also can be by the calling accumulation of some.For example, the user carries out a plurality of call by calls and approximately is exposed to identical RF energy the user who only carries out a calling in the identical time that coexists in a predetermined time period.
Since GW18 is a type of knowing user terminal in call setup from the ETI that launches at return link, the user terminal of some type may need not monitor.For example, it is contemplated that fixing user terminal 14a is placed on its antenna 13a from user position quite far away.And for car-mounted terminal, antenna 13a can protect the user to leave the RF energy of emission with this in the outside of vehicle 15 (Fig. 1).Therefore, according to ETI, GW18 can distinguish out the user terminal (for example handheld terminal) that the user is exposed to those types that possibility is the highest in the radiation RF energy.In addition, dissimilar handheld terminal (also by ETI identification), when the user handed in the normal operations position, the placement location of antenna 13a was possible different with respect to user's body.Like this, the value that is used to calculate user's radiation length (d) may be different for dissimilar user terminal 13, so just influenced the calculating of the average RF power density that GW18 carries out.Interested thresholding may be that fix or variable.
User terminal 13 also based on, for example, the power control information that receives from GW18 on the forward link, monitoring user terminal 13 emitted power, this also within the scope of the invention.The result of user terminal power-monitoring can be transmitted into GW18 by return link and use together with the result in conjunction with the GW18 power-monitoring.When decision stopped with being connected of specific user terminal 13, technology majority's agreement or some other can be used in GW18.Preferably, the priority height of any measured value of sending than user terminal 13 of the average power density determined of GW18.
When the calling of carrying out predefined type (for example, one 911 call out), it also is preferred that the business that allows user terminal refusal GW to initiate is cut off.In this case, GW18 determines that from the telephone number that sends with call connection request the user dialled in one group of predetermined number, and this calling is connected to PSTN.
After having connected the user who does one of predefined type calling, GW18 can send an information to user terminal 13, information of this terminal demonstration (and/or ringing a sound) indication customer call is connected finish, even GW18 has determined that this user terminal is above the average power density thresholding.
Preserve the record of relevant user RF exposure data and during the user is determined above thresholding in any calling of connecting (for example, emergency calls) record, and periodically from GW18, transmitting these information to GOCC36 by GDN39, these are also within the scope of the invention.GOCC36 can file these data also/or for the statistics purpose use this data.
When the present invention has at length been represented and has been described with reference to its preferred embodiment, those skilled in the art will appreciate that and under situation about not departing from the scope of the present invention with spirit, make therein in form and the change on the details all is fine.
For example, it is apparent that to one skilled in the art that notion of the present invention is not limited to satellite communication system, nor be limited to spread spectrum communication system.For example, time division multiple access (TDMA) system also can be benefited from notion of the present invention.Therefore notion of the present invention can generally be used for wireless communication system, here gateway, base station, mobile switching centre and a similar thing can both determine that the user is exposed to the degree of RF energy at far-end, and can temporarily refuse or be restricted to a user's business based on the degree of exposure of determining.
Further laudable is in the satellite communication system of some type, and for example satellite can be carried out the system that handles on the star for communication link, and satellite itself can be carried out function for monitoring all or a part of user terminal emittance as mentioned above.
Claims (26)
1. the method for an operation communication system may further comprise the steps:
Set up the wireless connections of and user terminal by a forward link and return link;
Determine in connection procedure whether the average transmit power density that is associated with a user terminal antenna with respect to a user of terminal, will equal or exceed at least one predetermined thresholding in an official hour unit, and an absolute thresholding; With
Stopped this connection equal or exceed time of thresholding at the average transmit power density level before.
2. method as claimed in claim 1, but also comprise such step:
The trial of setting up second connection of response user terminal within the time interval after the executive termination step, refusal is set up second connection.
3. method as claimed in claim 1, but also comprise these steps:
The trial of setting up second connection of response user terminal within the time interval after the executive termination step will be compared with the telephone number telephone number concentrated with belonging to a predetermined phone numbers that connection request is launched, and
If the telephone number matches that telephone number and this telephone number are concentrated then connects this user terminal, handle the calling of this telephone number.
4. method as claimed in claim 1, wherein determining step comprises these steps:
The signal that sampling receives on return link from user terminal;
By power control signal of forward link emission to user terminal on a predetermined level, to set up the transmitting power of user terminal; And
The transmitting power of user terminal expectation is transformed to the power density values of relative user's body.
5. the establishment step in the method as claimed in claim 1 also comprises these steps:
The type that from return link, receives from identification user terminal in the information of user terminal; And only when being identified as in one or more predetermined types one, the type of user terminal carries out determining step.
6. method as claimed in claim 1, but also comprise these steps:
In connection procedure, determine to be associated with the transmitting power density of user terminal antenna at user terminal; And the transmitting power density of determining by return link emission from user terminal.
7. the termination step in the method as claimed in claim 1 also comprises these initial step:
Launch an information on the forward link to user terminal; And
The emission information that response receives proposes the indication that a connection will be terminated very soon to the user of user terminal.
8. the step of setting up wireless connections in the method as claimed in claim 1 is set up by at least one satellite.
9. a communication system comprises:
Set up the device of wireless connections by a forward link and a return link and a user terminal;
In connection procedure, determine, whether the average transmit power density that is associated with a user terminal antenna will equal or exceed in an official hour unit, subscriber-related with a terminal, the thresholding that at least one is predetermined, the perhaps device of an absolute thresholding; With
Equal or exceed the device that stops this connection before time of thresholding at the average transmit power density level.
10. the response of the apparatus for establishing described in system as claimed in claim 9 user terminal is set up the trial of second connection within the time interval connection is terminated after, refuses to set up second connection.
11. the response of the apparatus for establishing described in system as claimed in claim 9 user terminal is set up the trial of second connection within the time interval after connection is terminated, to compare with the telephone number telephone number concentrated that connection request is launched with belonging to a predetermined phone numbers, if and a telephone number and a concentrated telephone number matches of this telephone number, then connect this user terminal, handle the calling of this telephone number.
12. the definite device described in system as claimed in claim 9 comprises:
The device that sampling receives on return link from the signal of user terminal;
By power control signal of forward link emission to user terminal on a predetermined level, to set up the device of the transmitting power of user terminal; And
Is the device of the power density values of relative user's body with the transmitting power of user terminal expectation as the functional transformation of time.
13. the apparatus for establishing described in system as claimed in claim 9 comprises the device from identification type of user terminal in the information of user terminal that receives from return link; And wherein said definite device responds a kind of definite user terminal identification, only just operates when user terminal is identified as in one or more predetermined types one.
14. the user terminal described in system as claimed in claim 9 is included in the device of the transmitting power density of determining to be associated with a user terminal antenna in the connection procedure; With the device of launching the transmitting power density of determining from user terminal by return link.
15. comprising, the termination device described in system as claimed in claim 9 launches the termination device of an information on the forward link to user terminal; And wherein said user terminal comprises the emission information that response receives, and proposes the device of the indication that a connection will be terminated very soon to the user of user terminal.
16. a system as claimed in claim 9 also comprises at least one satellite, sets up wireless connections by it.
17. a satellite communication system comprises:
One Earth One Family orbiter constellation;
At least one is positioned at the user terminal on land;
At least one is positioned at the gateway on land, and this gateway comprises by at least one above-mentioned satellite, between a terrestrial communications systems and above-mentioned at least one user terminal one of transmission two-way, the device that the radio communication of power control connects;
Wherein, at least one above-mentioned gateway is included in the connection procedure always to be determined in the power control information of user's terminal, whether the average transmit power density that is associated with a user terminal antenna will equal or exceed in an official hour unit, subscriber-related with a terminal, the thresholding that at least one is predetermined, the perhaps device of an absolute thresholding and stopped this device that is connected before the time that equals or exceeds thresholding at the average transmit power density level.
18. a gateway response user terminal described in the system of claim 17 is set up the trial of second connection within the time interval after connection is terminated, refusal is set up second connection.
19. a gateway response user terminal described in the system of claim 17 is set up the trial of second connection within the time interval after connection is terminated, to compare with the telephone number telephone number concentrated that connection request is launched with belonging to a predetermined phone numbers, if and a telephone number and a concentrated telephone number matches of this telephone number, then connect this user terminal, handle the calling of this telephone number.
20. the definite device described in the system of claim 17 comprises:
The device that sampling receives on return link from user terminal signal;
By power control signal of forward link emission to user terminal on a predetermined level, to set up the device of the transmitting power of user terminal; And
The transmitting power of user terminal expectation is transformed to the device of the power density values of relative user's body.
21. the gateway described in the system of claim 17 comprises the device from identification type of user terminal in the information of user terminal that receives from return link; And wherein said definite device responds a kind of definite user terminal identification, only just operates when user terminal is identified as in one or more predetermined types one.
22. user terminal described in the system of claim 17 is included in the device of the transmitting power density of determining to be associated with user terminal antenna in the connection procedure; With the device of launching the transmitting power density of determining from user terminal by return link.
23. comprising, the user terminal described in the system of claim 17 launches the termination device of an information on the forward link to user terminal; And wherein said user terminal comprises the emission information that response receives, and proposes the device of the indication that a connection will be terminated very soon to the user of user terminal.
24. it is that a spread-spectrum, CDMA radio communication connect that two-way described in the system of claim 17, the radio communication of power control connect.
25. it is that a TDMA radio communication connects that two-way described in the system of claim 17, the radio communication of power control connect.
26. a satellite communication system comprises:
At least one earth-orbiting satellite;
At least one is positioned at the user terminal on land; With
At least one is positioned at the gateway on land, and this gateway comprises by above-mentioned at least one satellite, the device that two-way radio communication of transmission connects between a terrestrial communications systems and above-mentioned at least one user terminal;
Wherein, at least one above-mentioned gateway, above-mentioned at least one satellite and above-mentioned at least one user terminal be included in the user who determines to be associated with terminal at least one connection procedure the RF radiation device and according to the device of the user RF exposure extent control wireless connections of determining.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 96109923 CN1156354A (en) | 1995-07-13 | 1996-07-12 | Satellite communications system having user RF exposure monitoring and control |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US502,151 | 1990-03-30 | ||
| CN 96109923 CN1156354A (en) | 1995-07-13 | 1996-07-12 | Satellite communications system having user RF exposure monitoring and control |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1156354A true CN1156354A (en) | 1997-08-06 |
Family
ID=5120711
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 96109923 Pending CN1156354A (en) | 1995-07-13 | 1996-07-12 | Satellite communications system having user RF exposure monitoring and control |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1156354A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104883435A (en) * | 2015-04-30 | 2015-09-02 | 广东欧珀移动通信有限公司 | Method and apparatus of minimizing radiation of terminal |
-
1996
- 1996-07-12 CN CN 96109923 patent/CN1156354A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104883435A (en) * | 2015-04-30 | 2015-09-02 | 广东欧珀移动通信有限公司 | Method and apparatus of minimizing radiation of terminal |
| CN104883435B (en) * | 2015-04-30 | 2018-01-23 | 广东欧珀移动通信有限公司 | One kind reduces terminal radiation method and its device |
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