In a UWB antenna having an upper dielectric member, a lower dielectric member, and a conductor pattern interposed therebetween, the conductor pattern has a feeding point at a generally center portion of a front surface of the antenna. The conductor pattern further has an inverted triangular portion including a right tapered portion and a left tapered portion extending from the feeding point towards right and left side surfaces of the antenna, respectively. A main expanding portion expands from an upper side of the inverted triangular portion. A right expanding portion and a left expanding portion expand from the right and the left tapered portions of the inverted triangular portion, respectively.

This invention relates to an antenna unit and, in particular, to an antenna unit for an ultra wideband (UWB).
The UWB technology means an ultra wideband radio technology and is a broad term representative of a radio transmission system that occupies a bandwidth of at least 25% of a center frequency or a bandwidth wider than 1.5 GHz. Briefly speaking, the UWB technology is a revolutionary radio technology for carrying out communication using short pulses (typically having a pulse width of 1 ns or less) of an ultra wideband.
A key difference between the UWB technology and the traditional radio technology is presence or absence of a carrier wave. In the traditional radio technology, a sinusoidal wave having a certain frequency, called a carrier wave, is modulated in various manners to transmit and receive data. On the other hand, the UWB technology does not use the carrier wave but uses the short pulses of an ultra wideband as described above.
The traditional radio technology uses a narrow frequency band. This is because communication using a narrow frequency band allows an effective use of a radio wave which is a finite resource.
As understood by its name, the UWB technology uses an ultra wide frequency band. Nevertheless, the UWB technology occupying an ultra wideband attracts increasing attention. The reason resides in output energy at each frequency.
In the UWB technology, the frequency band is very wide but output power at each frequency is very low. Since the output power has a very low level below a noise level, an interference between UWB communication and other radio communications is extremely small.
On the other hand, the UWB communication extends over an ultra wideband which overlaps frequency bands of existing radio communication services. Therefore, the band for the UWB communication is limited to a range from 3.1 GHz to 10.6 GHz at present.
In the meanwhile, an antenna basically utilizes a resonance phenomenon. The antenna has a resonance frequency determined by its length. In the UWB communication including a number of frequency components, it is difficult to cause a resonance. As a frequency band of a radio wave to be transmitted is wider, it is increasingly difficult to design the antenna.
For example, a patch antenna is known as a compact antenna. As an example of the patch antenna, a compact flat patch antenna is disclosed, for example, in Japanese Unexamined Patent Application Publication (JP-A) No. H7-94934. The flat patch antenna is excellent in portability, high in frequency temperature characteristic, suppressed in variation of the resonance frequency, and excellent in reliability. A patch antenna unit adaptable to a plurality of frequencies is disclosed, for example, in Japanese Unexamined Patent Application Publication (JP-A) No. H10-190347.
However, the patch antenna does not cover a wideband and is therefore unsuitable for use as a UWB antenna.
In the meanwhile, TAIYO YUDEN CO., LTD., Tokyo, Japan has successfully developed a very small ceramic chip antenna for UWB which is recognized as a next-generation technology that will simultaneously achieve high-rate data transmission and low power consumption in the field of short-range radio communication. The ceramic chip antenna has a size of 10 mm×8 mm and a thickness as small as 1 mm. By the development of the ceramic chip antenna, the UWB technology traditionally limited to military applications is now released for commercial use, for example, high-speed connection of data between digital equipments such as a PDP (Plasma Display Panel) television and a digital camera. It is therefore possible to miniaturize various equipments, including mobile equipments.
Such a UWB antenna may be used for various applications such as Bluetooth (registered trademark) and wireless LAN (Local Area Network).
Bluetooth is an open standard for an advanced technology for realizing wireless data and voice communication in a relatively short range between desktop and notebook computers, PDAs (Personal Digital Assistants), mobile telephones, printers, scanners, digital cameras, and home electric appliances, and so on. Bluetooth is operable using a radio wave in a worldwide available 2.4 GHz band and, therefore, can be used throughout the world. Briefly speaking, use of Bluetooth makes it possible to connect digital peripheral devices without cables. Therefore, any trouble associated with cable connection is a matter of the past.
The wireless LAN is a LAN using a transmission path, such as a radio wave or an infrared ray, except a cable and a wire.
As described above, an existing antenna such as a patch antenna is disadvantageous in that it is difficult to cover a wideband and waveform distortion (waveform broadening or widening) occurs. Further, an antenna characteristic is excellent if a voltage standing wave ratio (VSWR) is as low as possible. However, the existing antenna can not lower the VSWR in a high-frequency range. In other words, the VSWR inevitably becomes high in a high-frequency range.


A wireless communication apparatus employing spread spectrum modulation which detects and eliminates interference waves and temporarily stops and restarts communication for maintaining fine communication status. If the interference wave frequency band is known, a reception signal of the frequency band is eliminated. Communication is temporarily halted and restarted corresponding to interference occurrence period and/or radiowave propagation condition, and communication status is notified to a user. Further, if the interference wave occurrence period is unknown, the frequency of the interference wave is detected and a signal of the detected frequency is eliminated. In a case where communication is performed in packet form, the number of packets which can be transmitted sequentially without receiving reception confirmation is controlled based on the radiowave propagation condition. Moreover, a reception signal can be divided into a plurality of frequency band signals and interference wave detection can be performed in band signal units.

The present invention relates to a spread spectrum modulation communication apparatus and, more particularly, to a spread spectrum modulation communication apparatus which can detect or eliminate interference waves and maintain stable communication quality.
Generally, wireless communication apparatuses employing spread spectrum modulation are known for high anti-interference wave capability. Even if there exists a narrow-band interference wave within a reception band, the interference wave is spread in the spread spectrum demodulation process. The voltage of the demodulated interference wave becomes approximately 1/spread ratio (hereinafter, the spread ratio is represented by "s").
Accordingly, in comparison with a conventional narrow band system, the voltage of the anti-interference wave capability of the spread spectrum modulation type communication apparatus can be s times. FIGS. 42A to 42C show waveforms on reception in the spread spectrum modulation type communication apparatus (hereinafter, simply referred to as "communication apparatus"). FIG. 42A shows a spectrum signal waveform at a receiving terminal of the communication apparatus, FIG. 42B, a spectrum signal waveform after spread spectrum demodulation; and FIG. 42C, a spectrum signal waveform after passing through a narrow band-pass filter and before data demodulation.
However, if the communication apparatus and the conventional narrow band system share the same frequency, narrow band interference occurs so often. The interference wave power may become very large depending on the setting position of a receiving apparatus and exceed the anti-interference wave capability of the apparatus. In such case, it is impossible to maintain stable communication quality.
FIGS. 43A to 43C show signal waveforms in the above case. More specifically, FIG. 43A shows a spectrum signal waveform at the receiving terminal of the communication apparatus; FIG. 43B, a spectrum signal waveform after spread spectrum demodulation; and FIG. 43C, a spectrum signal waveform after passing through the narrow band-pass filter and before data demodulation.
Apparently, a non-negligible interference wave remains in a signal after spread spectrum demodulation and filtering by the narrow band-pass filter (FIG. 43C).
If the communication apparatus is used for digital data wireless communication, a communication protocol including an error correction procedure and a retransmission procedure is required for maintaining communication quality. For this reason, the data is transmitted in packet mode and the protocol is realized by, e.g., HDLC (High level Data Link Control) procedure.
FIGS. 44 and 45 show an example of the retransmission procedure according to the HDLC procedure. More specifically, FIG. 44 shows a rejection procedure (Rej) and FIG. 45 shows a selective rejection procedure (SRej).
In FIG. 44, a data transmitting apparatus (hereinafter, referred to as "transmitter") transmits a data packet (I), and one portion having a frame number "1" and a packet number "5" (I.sub.1-5) fails to reach the data receiving apparatus (hereinafter, referred to as "receiver").
The receiver waits until time set to reception confirmation timer T2 becomes "over", then transmits an RR (receive ready) signal and starts retransmission timer T1. Thereafter, the receiver waits for a response from the transmitter.
On the other hand, the transmitter transmits the I.sub.1-5 in which a poll bit (P: reception confirmation request bit) is set to "1" and starts the timer T1, thereafter, waits for confirmation till time set to the timer T1 becomes "over".
However, in FIG. 44, the transmitter cannot receive the RR signal from the receiver due to a communication condition, the time set to the timer T1 at the transmitting side becomes "over". Accordingly, the transmitter clears the timer T1 and restarts it, and at the same time transmits an RR signal in which the poll bit is set to "1". If there is no response from the receiver until the time set to the timer T1 becomes "over" again, the transmitter repeats the above retransmission up to N.sub.2 times.
If the communication condition is reactivated and communication between the apparati becomes possible, the receiver compares a transmission status variable (T.sub.s : value indicating a confirmed data packet number from the transmitter+1) indicated by RR signal and a reception status variable (Rs: value indicating a data packet number correctly received by the receiver). If the variables T.sub.s and R.sub.s are different, the receiver requests retransmission, i.e., transmits a Rej command in which the reception status variable R.sub.s is set as a reception sequence number to the transmitter.
The transmitter receives the Rej command and retransmits the I.sub.1-5 data corresponding to the reception sequence number included in the Rej command. As the poll bit of the data is "1", the transmitter waits for an RR signal having a variable R.sub.s corresponding to the T.sub.s from the receiver. Upon receiving the RR signal, the transmitter restarts to transmit the next data (I).
Next, the SRej (Selective Rejection) procedure will be described with reference to FIG. 45. In FIG. 45, only procedures different from the Rej procedure will be explained. As shown in FIG. 45, the poll bit (P) is not set to "1", i.e., the reception confirmation is not made, and the receiver does not receive data I.sub.1-3 but correctly receives the next data I.sub.1-4.
The receiver transmits a SRej command in which a parameter indicating a reception number of the not-received data I.sub.1-3 to request retransmission. At this time, if the communication condition is fine, the transmitter that receives the SRej command during transmission (I.sub.1-4) retransmits the data I.sub.1-3 immediately after the transmission of the data I.sub.1-4. Thereafter, the transmitter continues transmission in the initial transmission order.
In the above-described communication according to the HDLC procedure, the lack of data can be retransmitted as far as the degradation of communication condition is recovered in a short period. However, if the degradation of communication condition continues over seconds, the retransmission should be repeated up to the maximum number of retrying times set in the protocol as shown in FIG. 46. As a result, the data link might be disconnected.
Such repetition of retransmission up to the maximum number of times, the disconnection and re-establishment of the data link lower the throughput. In addition, the transmission of radiowaves in non-communicable status has ill effects on the radiowave propagation condition, which further influences the other wireless communication systems, causing problems in common use of radiowave resources.
In a system having only the Rej retransmission procedure, the transmitter sequentially performs data transmission up to an outstanding number (maximum number of times within which transmission without reception confirmation is possible). In a system which performs time division bidirectional communication, if a lack of packet occurs when the number of transmitted packets is small, the received data from the lacked packet data to the data at the outstanding number are deleted from the receiver. Accordingly, when the transmitter retransmits the lacked data at a point where the communication condition is reactivated, the transmitter should retransmit data from the head data, thus lowering the throughput. Further, the transmission of radiowaves in non-communicable status, for a long period, ill effects the radiowave propagation condition.
In a system having a combination of the SRej and Rej procedures, the outstanding number can be set to a greater number and the lowering of throughput can be improved. However, in order to increase the outstanding number, the storage capacity should be enlarged, and the protocol control becomes complicated. The enlarged system hardware causes an increase in manufacturing costs as well as difficulty in downsizing of the apparatus.
In the transmitting apparatus for the spread spectrum modulation, if the band is spread to a fully broad band with respect to its data transfer speed, the influence of interference waves can be ignored. In this case, if the spread spectrum (SS) signal is multiplexed in the same frequency band, it does not seriously influence the spread spectrum transmission efficiency.
However, if an intense external interference wave such as a microwave from radar and a microwave oven intrudes into the receiving apparatus during the multiplexing, it lowers the transmission efficiency, since the number of available channels and transmission capacity are restricted depending upon the size of the interference wave.
In one proposed method for improving the degradation of the transmission efficiency, increasing processing gain in the spread spectrum modulation communication system is used (hereinafter, referred to as "SS communication system).
However, in this method, widening of the spread bandwidth causes a band restriction problem and difficulties in initial synchronization seizure. For this reason, the processing gain cannot be increased without limitation. Another method for directly eliminating or reducing the interference wave is desired for improving the transmission efficiency in the SS communication system.
FIG. 47 shows a demodulator in the conventional SS communication system for eliminating/reducing interference wave.
In FIG. 47, a reception signal which enters input terminal a includes communication wave d(t), interference waves U.sub.s (t) and U.sub.i (t). U.sub.s (t) is an arbitrary spread spectrum interference wave; and Ui(t), a noise component and the other SS interference wave component.
In the method employed in the modulator of FIG. 47, spread spectrum demodulator (SSDEM) 831 spread-spectrum-demodulates the SS interference wave. After the S/N ratio is raised by narrow band-pass filter (narrow BPF) 832, spread spectrum modulator (SSMOD) 833 spread-spectrum-modulates the demodulated wave and supplies the reproduced SS interference wave to a negative (-) input terminal of subtracter 834. On the other hand, delay circuit 830 matches the phase and amplitude of the reception signal to the reproduced SS interference wave and supplies the reception signal to a positive (+) input terminal of the subtracter 834. Finally, the subtracter 834 subtracts the SS interference wave from the input signal.
It should be noted that the narrow BPF 832 can be replaced with a narrow band elimination filter such as narrow band elimination filter (BEF) 835 in FIG. 48. In this case, after the SS demodulation by the SSDEM 831, the narrow BEF 835 eliminates a narrow band SS demodulated signal, and the SSMOD 833 modulates the signal to reproduce a desired signal.
FIG. 49 shows another example of the demodulator. In FIG. 49, the interference wave included in the reception signal is eliminated by the narrow BEF 835 before SS demodulation by SSDEM 836.
FIG. 50 is a block diagram showing a detailed construction of the SSDEM 836. In FIG. 50, the SSDEM 836 comprises high pass filters (HPF) 837 and 838, multiplier 839 and low pass filter (LPF) 840.
The HPF's 837 and 838 can be replaced with LPF's, if their passing characteristics are the same. Cutoff frequency f.sub.c of the HPF's 837 and 838 corresponds to a point where the energy is approximately half of the mainrobe of the SS signal generated in the transmitter (not shown).
Next, the interference wave elimination by the SSDEM 836 will be described with reference to signal waveforms in FIG. 51.
In FIG. 51, waveform (a) denotes the information signal D having only the lower component spectrum before data spread by the transmitter (not shown); and waveform (b), a SS demodulated wave D.sub.ss in which the siderobe of the signal spread by the modulator using a spread code has been eliminated.
In mid-course of the transmission of the D.sub.ss wave by the transmitter via an antenna (not shown) of the receiver to the input terminal a in FIG. 50, mixture of interference wave easily occurs in the space propagation path. In FIG. 51, waveform (c) represents the D.sub.ss wave in which an intense interference wave is mixed.
In the demodulation by the SSDEM 836, lower frequency component from the cutoff frequency of the input signal from an input terminal a ((c) in FIG. 51) is reduced by the HPF 837 to obtain a spectrum signal d(D'.sub.ss +U')
On the other hand, a spread signal P ((e) in FIG. 51) spread-modulated using the same spread code as that in the modulator of the transmitter is inputted from input terminal b. Also, lower frequency component from the cutoff frequency of the signal P is reduced to obtain a signal P' as shown in FIG. 51 (f). The signal P' and the signal d(D'.sub.ss +U') are provided to the multiplier 839 in which the d(D'.sub.ss +U') is demodulated, and a signal g(U'.sub.ss +D') is obtained. The signal g(U'.sub.ss +D') passes through the LPF 840, by which the interference wave and the spread-interference wave are eliminated, then only demodulated information signal D' ((h) in FIG. 51) can be outputted from output terminal c.
However, the above interference wave elimination method has a problem in that the noise component (noise component in the narrow BPF after the inverse-spread) remains in the demodulated information signal. Further, the conventional method is effective only if the frequency of interference wave is already-known. However, it is not effective against interference wave having an unknown frequency.
The SS communication apparatus has a variable attenuator for changing the damping rate to maintain a constant output voltage with respect to voltage variation of a reception radiowave.
FIG. 52 is a block diagram showing an intermediate frequency amplifier (IF AMP) with an automatic gain controller (AGC) which is generally used in an IF AMP. In FIG. 52, amplifiers (AMP's) 930, 932 and 933 respectively amplify an input signal. A portion surrounded by a broken line A generates a DC control voltage for controlling the damping rate of variable attenuator (variable ATT) 931. First, AMP 934 amplifies diode normal direction voltage used for envelope detection (to be described later) so that the voltage can have a fully large amplitude. Envelope detector 935 detects an envelope, then, integrator 936 converts the envelope into DC voltage, further, DC amplifier (DCAMP) 937 amplifies the DC voltage to obtain feedback loop gain. Thus, the output level variation with respect to the input level variation can be suppressed.
The AGC voltage generated in the above manner controls the variable ATT 931 which changes its damping rate to absorb the variation of the input voltage, thus a constant output voltage can be maintained. Especially, as SS modulated signals have a broad band, using an attenuator is effective. The conventional AGC varies the damping rate using e.g. PIN diode.
FIG. 53 is a block diagram showing the configuration of a conventional SS communication apparatus using the AGC in FIG. 52. This SS communication apparatus, performs half-duplex communication.
In FIG. 53, antenna 441 is used for both transmission and reception. Antenna switch (ANTSW) 462 switches over the transmission/reception of the antenna 441 by switchover signal S.sub.11. The ANTSW 462 comprises a semiconductor switch utilizing PIN diode characteristics such as a high-frequency relay.
Further, the SS communication apparatus has a band-pass filter (BPF) 442 for eliminating unnecessary radiowave included in a reception signal, low-noise RF amplifier (RF AMP) 443 which amplifies the reception signal, local oscillator (local OSC) 444 for frequency conversion, mixer 445 which multiplies the signal from the local OSC 444 and the reception signal, BPF 446 for taking an IF frequency out of the output signal from the mixer 445, variable attenuator (ATT) 463 which attenuates the output from the BPF 446, AMP 447 which amplifies the attenuated signal outputted from the ATT 463, and correlator 448 for detecting a correlation peak in a spread code with respect to the reception signal.
Further, the SS communication apparatus has a delay device 449 which delays the correlation output, mixer 450 which multiplies the relayed output from the delay device 449 and the output from the correlator 448, LPF 451 which cuts off a high-frequency zone of the mixer 450 output, envelope detector 453 which detects an envelope in the output from the correlator 448, integrator 454 which integrates the detected signal outputted from the envelope detector 453, clock regenerator 456 which regenerates a clock from the detected signal, comparator 452 which judges the level of the LPF 451 output, and comparator 455 which judges the level of the integrator 454 output.
Further, the SS communication apparatus has reference oscillator (reference OSC) 457 for transmission, PN code generator 458 which adds a PN code to a transmission signal, mixer 459 which multiplies the transmission signal and the reference-oscillated frequency, mixer 460 which multiplies the frequency signal from the local OSC 444 and the reception signal, and RF amplifier (RF AMP) 461 which amplifies the transmission signal and outputs the signal to the ANTSW 462.
Upon transmission in the SS communication apparatus having the construction as described above, a controller (not shown) transmits an ON signal (S.sub.12) for the RF AMP 461 and a switchover signal S.sub.11 to switchover the ANTSW 462 to the antenna 441 side.
The mixer 459 modulates transmission data with a random code ((b) in FIG. 54) outputted from the PN code generator 458 and a carrier signal ((a) in FIG. 54) from the reference OSC 457 to obtain a spread signal ((c) in FIG. 54).
The mixer 460 converts the spread signal with the reference signal from the local OSC 444 into an RF frequency. The RF AMP 461 amplifies the RF frequency and supplies the amplified RF frequency to the antenna 441 via the ANTSW 462.
Upon reception, the controller transmits a switchover signal S.sub.11 to switchover the antenna 441 by the ANTSW 462 to the reception side. The reception signal passes through the RF PBF 442, where unnecessary waves are eliminated and only a desired signal is outputted.
The RF AMP 443 amplifies this signal and inputs the amplified signal into the mixer 445, which converts the signal from the RF AMP 443 with a predetermined frequency signal from the local OSC 444 into an IF frequency (hereinafter, referred to as "IF signal").
Next, only the IF frequency component is taken out of the IF signal in the BPF 446, and the ATT 463 attenuates the IF frequency component signal in accordance with AGC voltage to supply a constant voltage IF signal to the correlator 448. In the correlation output from the correlator 448 ((a) in FIG. 55), the correlation output peak interval is proportional to transmission data speed (T.sub.1). This correlation output is supplied to the envelope detector 453 and the delay device 449. The delay device 449 delays the correlation output by one bit of the transmission data ((b) in FIG. 55), and the mixer 450 multiplies the correlation output before delay and the delayed correlation output to obtain demodulation output ((c) in FIG. 55).
The demodulation output passes through the LPF 451, in which high-frequency component is eliminated. The comparator 452 judges the level of the demodulation output, and finally, reception data ((d) in FIG. 55) can be obtained. Note that as it is understood from the above description, the demodulator of this SS communication apparatus is a differential demodulator.
On the other hand, the envelope detector 453 detects an envelope out of the supplied correlation output and the envelope detection output ((a) in FIG. 56) is obtained. This detection output is inputted into the clock regenerator 456 in which clock component is extracted, and finally, reception clock ((c) in FIG. 56) is obtained.
Further, the envelope detection output is also supplied to the integrator 454 which converts the detection output into DC voltage corresponding to the peak level ((c) in FIG. 56). The DC voltage is used as the AGC voltage for controlling the damping rate of the ATT 463. The output of the integrator 454 is supplied to the comparator 455, which determines whether or not there is a desired voltage level, i.e., whether or not there is a reception signal, and outputs the integrator output as a carrier sense signal to the controller.
However, in the above SS communication apparatus, if the interference wave mixes in a reception signal, the effect of the interference wave appears in the correlation output (e.g., (a) in FIG. 57), degrading the correlation output S/N ratio.
Further, a signal other than the correlation output, e.g., the input voltage of the correlator, may directly appear as the correlation output. If AGC voltage is generated using such correlation output in the conventional manner, the envelope detection output may include its noise component ((b) in FIG. 57). Accordingly, the AGC voltage whose level corresponds to the correlation output noise ((c) in FIG. 57) may be generated, which becomes an impediment of exact automatic gain control.
For bidirectional communication by this SS communication apparatus, a full duplex system for simultaneous transmission/reception and a half duplex system for alternative transmission/reception can be considered. The former system comprises a transmission band and a reception band respectively. The latter system switches over the transmission/reception using a filter, a relay and a semiconductor switch.
As the full duplex system needs both transmission and reception frequency bands, this system is not advantageous in comparison with the latter system in consideration of effective use of frequency. However, it has many advantages in its configuration; e.g., it does not need transmission/reception switching control, and the system throughput can be raised. However, if this system is applied to a communication apparatus which can raise the system capability by using a wide band, such as a spread spectrum modulation communication apparatus, the apparatus should use an extremely wide frequency band in order to have dedicated transmission and reception bands. Thus it cannot attain the effective frequency use.
Accordingly, the system as shown in FIG. 53 performs the half-duplex communication, and it has the ANTSW 462 for switching over transmission/reception with the switchover signal S.sub.11.
FIG. 58 is a block diagram showing the half-duplex communication highlighting the switching over of the ANTSW 462.
Half-duplex communication using a common antenna depends on separation of transmission from reception by the ANTSW 463. In order to prevent receiver 1000 from directly receiving a transmission signal, a high-frequency relay having excellent isolation is employed.
FIG. 59 is a block diagram showing the configuration of a SS communication apparatus using a high-frequency relay as an ANTSW. The construction shown in FIG. 59 corresponds to that in FIG. 53 except high-frequency relay 480 and AGC control by amplifier 447 in place of the damping rate control by the ATT 463. Therefore, the correspondent elements have the same reference numerals and the explanations of these elements will be omitted.
In FIG. 59, the high-frequency relay 480 can provide a 40 dB to 50 dB transmission/reception isolation with respect to a 2 GH.sub.z to 4 GH.sub.z frequency.
FIG. 60 is a block diagram showing the configuration of a SS communication apparatus using semiconductor switch 481 instead of the high-frequency relay 480. Similarly to FIG. 59, the elements corresponding to those in FIG. 53 have the same reference numerals and the explanations of these elements will be omitted.
In the apparatus of FIG. 60, a transmission/reception isolation can be about 30 dB with respect to about 2 GH.sub.z frequency. Power supply to the RF AMP 443 and the IF AMP 447 in the receiver is halted by switchover signal S.sub.13 to ensure transmission isolation.
In the apparatus of FIG. 59, because the high-frequency relay 480 is very expensive and the device size is large, downsizing of the system and cost reducing are difficult. Further, response period to the switchover signal S.sub.11 is long, i.e., the interval from the applying of the switchover signal S.sub.11 to normal relay operation is several seconds, thus lowering the system throughput.
When intense external interference wave arrives within the band, the interference wave intrudes in the receiver during transmission. The receiver amplifies the received signal including the interference wave, and the noise exists in the correlation output. As a result, erroneous operations such as generating a carrier sense signal may occur.
FIG. 61 shows signal waveforms respectively representing correlation output, demodulation output, detection output, AGC voltage and a carrier sense signal in case where interference wave has intruded in the receiver.
In the apparatus of FIG. 60, a conceivable problem occurs after the power supply to the RF AMP 443 and the IF AMP 447 is turned off and on again. When this occurs, operations of these AMP's become unstable, and it takes a long period to resume stable amplification operation. Thus, the throughput of the apparatus is extremely lowered.
Further, although the SS modulation communication is generally considered "tolerant of interference waves", if a radiowave transmitted in an intense output exceeding the anti-interference wave capability exists within the band, the apparatus is ill effected, causing degradation of communication quality and communication line disconnection.
Such interference waves cannot be predicted. Therefore, users cannot judge whether the cause of degradation of communication quality is the interference wave or not.
In present situations where using radiowaves in the same frequency band for different purposes has been considered, the above-described influences of the interference waves given to the SS communication apparatuses will be more serious.

Spread spectrum modulation communication apparatus for narrow band interference elimination


An electrode assembly includes an electrode configured for externally defibrillating a subject. The electrode assembly also includes a camera configured to capture an image of at least a portion of the subject's body. The image has sufficient information to enable the position of the electrode assembly relative to the subject's chest to be determined.

External defibrillators frequently include a pair of "hands-free" disposable electrodes, which are essentially flexible pads that are adhered to the skin of a subject having a cardiac event (i.e., used transcutaneously). The hands-free electrodes can be of the type that are adhered to a subject, rather than paddles that are held by a rescuer during defibrillation. Hands-free disposable electrodes typically include a non-conductive backing layer, a conductive layer, formed from a thin sheet of metal (e.g. tin or silver) or a conductive ink (e.g. silver-chloride) printed on a substrate, and a liquid or solid electrically conductive gel covering the electrically conductive layer so that electrical current passes through the gel to the subject's body. The area of contact between the gel and the subject's body where current is delivered is referred to herein as the "treatment area".


One or more display elements of an apparatus provide light representative of distant objects and near objects and at least one optical element of the apparatus is responsive to the light representative of the near objects, for providing video images of the near objects at one or more near focal lengths, and is responsive to the light representative of distant objects, for providing video images of the distant objects at one or more far focal length and positioned for viewing at an elevation above the video images of the near objects.

Still photography and motion picture capture by traditional film/cinematography or more recently by electronic means such as electronic still or video image capture rely on fixed focal length optics/lenses. For over a hundred years, viewing by a viewer or playback to a viewer, the captured imagery is presented for viewing at a static focal length, e.g., on a flat piece of paper in the case of photographs, emitted from a flat surface in the case of liquid crystal or plasma display, projected onto the back of a diffuse surface for viewing from the front, or projected onto a reflective surface such as a movie screen. In other words, the viewer's accommodation does not change while viewing images of different objects at different depths in different regions within the presented imagery. Even if the viewer's eyes change in convergence angle, as in stereoscopic video, the accommodation remains the same. This leads to cognitive discomfort.
U.S. Pat. No. 5,644,324 shows a method and apparatus for providing, in response to successive image signals and a control signal, the successive images at various apparent distances. If the images are stereoscopic, the harmonious natural relationship between accommodation and convergence may be preserved so as to avoid cognitive strain otherwise experienced by the viewer. The images may have a highly detailed component which has its image content changed according to changes in the direction of a monitored one or more visual axes. U.S. Pat. Nos. 6,094,182 and 6,246,382 disclose but claim different aspects of the same subject matter. Although stereoscopic motion pictures, computer generated stereoscopic imagery and video, and even consumer stereoscopic cameras have begun to be introduced, techniques for addressing accommodation have proved slow to become adopted in the present commercial marketplace due to inertia and perhaps also due to the relative complexity of the possible technical solutions and the attendant expense. There have been many devices disclosed along these lines over the last decade, notably from the University of Washington in a "scanned beam display with adjustable accommodation" by Tidwell et al (U.S. Pat. No. 6,281,862), and a "variable fixation viewing distance scanned light displays" by Schowengerdt et al (U.S. Patent Application Publication 2008/0117289). Another notable disclosure of a "3D autostereoscopic display with true depth perception" was recently disclosed by Ilya Agurok (U.S. Patent Application Publication No. 2011/0032482) but, so far as is known, none of the disclosed devices have so far actually been made or used in any consumer or military display device.
The above-mentioned traditional still photography and motion picture capture by fixed focal length optics/lenses has also been accompanied by those of skill in the art using narrow field of view lenses. There have been some efforts to change this situation, notably by Fred Waller in the "Cinerama" initiative of the 1950s in which imagery of the same scene taken from three relatively narrow field of view cameras were presented alongside each other to spectacularly increase the horizontal field of view presented in special theaters with three screens abutted side-by-side for a nearly seamless presentation. Although Cinerama presented a spectacular wide field of view, it failed not because audiences rejected it or grew bored with it (in fact it was a sensation at the time), but for other reasons, including the fact that there were too many problems involved with projecting three 35 mm films simultaneously. Moreover, exhibitors were reluctant to risk an investment in the necessary new equipment required to present a non-standard format. Studios/distributors no doubt feared that the success of any new infrastructure of this sort might seriously diminish the value existing films held in vaults, in circulation or, as yet unreleased.
What is needed is a way to bypass entrenched financial interests by providing new ways to capture and view still and video imagery that provides a wide field of view and that permits natural stereoscopic capture/viewing for both amateurs and professionals without high investment in infrastructure.

Apparatus for image display with multi-focal length progressive lens or multiple discrete lenses each having different fixed focal lengths or a variable focal length


A vehicle horn and control function switch that has compensation for wide temperature variations and preloads from surrounding material due to manufacturing processes and material aging. Due to the very thin physical thickness of the force sensor, the switch is useful when the sensors are mounted on the hub of a vehicle steering wheel adjacent to an airbag assembly. The switch comprises a force sensor and a temperature sensor mounted in the hub of a steering wheel. The force sensor is connected to the input of an operational amplifier that has an offsetting input network and an amplifying feedback network that are controlled from a programmable microcontroller. The output of the operational amplifier and the temperature sensor are connected to the programmable microcontroller. In operation, the programmable microcontroller reads a temperature signal from the temperature sensor and a quiescent force signal from the output of the operational amplifier and compensates the offsetting and amplifying of the operational amplifier for temperature variations and effects of preload conditions, respectively. When an actuating force signal applied to the force sensor, the force signal at an input to the programmable microcontroller exceeds a predetermined threshold and the programmable microcontroller activates an output, causing a horn or other control function to actuate.

The invention relates generally to vehicle horn and control function switch apparatus and, more particularly, to a vehicle horn and control function switch apparatus for steering wheel applications with compensation for effects of temperature and pre-loading. The invention also relates to a method of operation for the compensated switch apparatus.
From the advent of motor vehicles, there was a recognized need to gain the attention of people and animals that were in the path of a vehicle. As a result, the horn became a standard safety feature of motor vehicles, and was most swiftly and conveniently operated by a mechanical switch positioned in the center of the vehicle steering wheel. In more recent times, the airbag became another standard safety feature of motor vehicles. The most convenient location for the driver side airbag was the center of the vehicle steering wheel, collocated with the horn switch and other vehicle controls. In order to accommodate this addition, automotive designers turned to very thin electronic switch devices for horn actuation that could easily be positioned over an airbag cover. However, these devices suffered from the effects of temperature changes and static forces from adjacent components resulting from the manufacturing process or material aging characteristics.
These very thin electronic switch devices are usually fabricated from membrane material, piezoelectric elements, or pressure sensitive resistive ink, and require supporting electronic circuitry in order to function. U.S. Pat. Nos. 5,463,258 and 5,539,259 disclose identical circuits for sensing a resistive change in a force transducer due to applied forces, for turning on a transistor switch, for energizing a relay, and for activating a horn. Neither patent discloses any means of temperature or preload force compensation.
For reliable operation over extreme temperature ranges encountered in vehicle applications, compensation schemes are required for the very thin electronic switch devices. One such compensation scheme is described in U.S. Pat. No. 5,576,684. This scheme makes use of a flexible potentiometer that changes resistance as its shape changes as the user presses against the steering wheel hub cover. The horn control circuit responds to extremely rapid changes in the resistance of the flexible potentiometer, but not to more gradual changes caused by, for example, temperature changes. An analog to digital converter and a microprocessor are the primary circuit control components. Another similar approach is described in U.S. Pat. No. 5,398,962. The apparatus comprises a force sensor fabricated from pressure sensitive resistive material and disposed in a cover assembly mounted on the steering wheel. The sensor is connected to a circuit for sensing the change in applied force to the sensor during a predetermined wait period, for determining whether the change has reached a selected threshold value, and for activating or deactivating a horn if the change at least equals the selected threshold value. Yet another approach is disclosed in U.S. Pat. No. 5,489,806, which discloses a pressure or deflection sensitive horn switch with temperature compensation to compensate for changes in the plastic airbag cover stiffness due to changes in temperature. The sensors comprise both a temperature sensing device and a horn switch deflection sensing device operated by applied force mounted on the airbag cover surface and connected to an analog to digital converter controlled by a microprocessor. The microprocessor evaluates and compares the temperature and deflection signals to determine if the deflection of the cover surface is sufficient, when compensating for change in cover stiffness due to temperature change of the cover surface, to actuate a horn. Although these approaches provide for some temperature variation, it is not apparent that the wide sensor conductance variations with temperature of these sensing devices can be accommodated. There is also no disclosure of compensation for variations in preload forces due to manufacturing processes or material aging. Another related problem not addressed is the ability to maintain the maximum dynamic range of the force sensor relative to the fixed operating range of the supporting circuitry for all operating temperatures and preload conditions.
For reliable operation over extreme temperature ranges encountered in vehicle applications, there is a need for a horn and control function switch temperature compensation means that enables reliable operation over a temperature range from about -40.degree. C. to about +85.degree. C. In order to account for changes in preload forces resulting from the manufacturing process or vehicle component material aging, a horn and control function switch preload compensation means must enable reliable operation over a range of applied force to the switch sensor of from 1 Kg up to 5 Kg. Since, upon an applied force to the switch sensor of from 1 Kg up to 5 Kg, a typical resistance range of a horn and control function switch sensor is from 39 Kohms to 188 Kohms at -40.degree. C., and from 2 Kohms to 12 Kohms at 85.degree. C., there is a need to match this extremely wide dynamic sensor operating range to the fixed operating range of the control circuitry with suitable dynamic range compensation means. In addition to these requirements, the horn and control function switch, and associated circuitry must be easily and inexpensively fabricated, assembled, tested, calibrated, and installed.

Vehicle horn and control function switch with compensation and method of operation


A fishing hat comprises a crown, having a front and back, and a bill and blinder assembly. The bill and blinder assembly is made of a single piece of semi-rigid material and comprises a bill and two side blinders, each side blinder having front and back edges. The bill has a length ranging from about 95 mm to about 115 mm.. A sun shade for use with the fishing hat comprises a fabric and a holding means fixedly attached to the fabric. The holding means comprises a band that can be situated on and wrapped around the wearer's head such that the single fabric covers the wearer's ears and neck.

The present invention is directed to a fishing hat and sun shade particularly useful for sightfishing. Sightfishing is generally done in shallow water, usually from about six inches to about six feet deep. Sightfishing requires the fisherman to see the fish and present the bait or fly to a particular fish or target, such as a specific log or rock where fish may lay.
Seeing the fish is sometimes difficult because of sunlight reflecting off the water. Additionally, obstacles, such as moving or choppy water, make it difficult for the fisherman to see in the water. With saltwater sightfishing, many factors create movement, such as the wind, the tide, the current, the boat and the fish. In freshwater fishing, the rocks and logs on the bottom of the rivers and streams, as well as the high speed of the water, create ripples on the surface, again making it difficult for the fisherman to see through the water. When the water is clear, the surface glare and reflection make seeing even more difficult.
For years people have shielded their eyes from the sun by creating a shade with their hand above their eyes, thus leading to the creation of the hat bill. And for years fisherman have created peripheral shade with their hands cupped around their eyes. A need was thus created for a hat that incorporates both types of shade while leaving the wearer's hands free for other uses.
Currently available hats do not adequately block the sun, making it difficult for the fisherman to see the fish. For ideal vision, a fisherman would look through a tunnel that extends from his eyes to the water. The more the peripheral light is eliminated, the better the vision is. Additionally, it is desirable to have increased eye protection from the sun, hooks and lures.
Thus, a suitable sightfishing hat creates a tunnel effect while providing an aesthetically pleasing design. A hat that provides a shaded area around the face allows the wearer to see through the water without eye strain and provides much more clarity. Additionally, a fishing hat should be constructed of such a material so that it can float in the water in the case that it is blown off the fisherman's head.


A printed substrate, wherein a printed polymer layer is present on a surface of the substrate, is disclosed. The printed polymer layer includes a polymer selected from group consisting of one or more of polyvinyl chloride, a copolymer of vinyl chloride and vinyl acetate, and a terpolymer of vinyl chloride, vinyl acetate and ethylene; a plasticizer; a colorant; and calcium carbonate.

Inkjet printing is used in a variety of printing applications, and can provide high resolution coloured images on a range of substrates. Advantageously, the inkjet printing process provides high quality images. The process should achieve high optical density such that the amount of ink required to achieve the desired image is minimised.
In recent years, inkjet printing has been used in the production of wallpaper. In addition to a printed pattern, wallpaper typically has a resin layer that provides scratch and stain resistance and that also affects the appearance of the wallpaper. WO 2018/110518 describes a printing method that can be used to prepare surface coverings such as wallpaper. In the disclosed method, a liquid resin layer is applied to a substrate and a pattern is applied to the liquid resin layer by inkjet printing. The liquid resin layer with the pattern then undergoes curing such that the liquid resin layer undergoes a phase transition from liquid to solid. In the examples, a liquid plastisol resin layer composition is applied to fleece-backed paper. The plastisol composition is a dispersion of polyvinyl chloride polymer in an ester-based plasticiser.

Printed substrate and method for printing onto a substrate


Provided is a convolutional neural network system including a data selector configured to output an input value corresponding to a position of a sparse weight from among input values of input data on a basis of a sparse index indicating the position of a nonzero value in a sparse weight kernel, and a multiply-accumulate (MAC) computator configured to perform a convolution computation on the input value output from the data selector by using the sparse weight kernel.

The present disclosure herein relates to a deep neural network, and more particularly to a convolutional neural network system and an operation method thereof.
As a technology for image recognition, a convolutional neural network (CNN) is being actively researched which is one of deep neural network schemes. A neural network structure shows an eminent performance in various object cognition fields such as object recognition or handwriting recognition. In particular, the CNN provides very effective performance to the object recognition.
Recently, as an efficient CNN structure is suggested, a recognition ratio using a neural network reaches that of a human. However, the CNN has a very complex structure and requires a large amount of computations. Therefore a hardware acceleration scheme using a high performance server or a GPU is adopted. In the CNN structure, most computations generated in the inner side are performed using a multiply-accumulate (MAC) computator. However, since the number of connections between nodes in the CNN is very large and the number of parameters requiring multiplications is also large, a large amount of computations is required in a learning process or a recognition process and thus large hardware resources are required.

Convolutional neural network system and operation method thereof

ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE


An ultra-compact combination exhaust muffler and aftertreatment element and water trap assembly provides exhaust flow through an aftertreatment element surrounded by an annular water collection space receiving water diverted and shed from an upper dome cap above the aftertreatment element and below the upper outlet. In a further embodiment, the assembly includes housing sections separable from each other at a service joint axially between axial ends of the aftertreatment element for ease of servicing. In a further aspect, the aftertreatment element has an axial end within a housing section saving axial extension space.

The invention relates to vertical exhaust systems and exhaust water trap assemblies, including for heavy duty vehicles, such as trucks, tractors, off-road equipment, and the like which utilize a vertical exhaust system, for example in which the exhaust conduit extends vertically alongside the cab of the vehicle.
For reduced emissions, catalytic converters and soot filters have been incorporated in the exhaust system of buses, trucks, and so on. If the exhaust outlet is vertical, there is a possibility that water, such as rain, snow, or bus or truck wash, can enter the upper end of the exhaust system and flow downwardly into contact with the catalytic converter or soot filter unit. The water entering the system can be absorbed in the catalyst/filter mounting mat, e.g. vermiculite, that is typically located between the outer surface of the catalytic converter and the outer body of the exhaust conduit. Mounting mat that is exposed to water results in a much lower push-out force, a measure of the ability for the mat to retain the catalyst/filter in place. In another scenario, freezing of water in the catalytic converter can cause structural damage to the monolithic catalyst. As an additional problem, water flowing through the catalytic converter or soot filter may tend to wash particulate material downwardly where such material collects and clogs the lower surface of the catalytic converter/soot filter causing premature failure thereof.
The present invention arose during continuing development efforts directed toward an improved combination exhaust muffler and aftertreatment element and water trap assembly, including ultra-compact structure.

Compact combination exhaust muffler and aftertreatment element and water trap assembly


A surface treatment method of a polyamide resin composition molded article is disclosed, comprising bringing the surface of a polyamide resin composition molded article into contact with water, said polyamide resin composition molded article comprising (C) 100 parts by weight of a resin composition comprising (A) from 10 to 80% by weight of a polyamide resin and (B) from 20 to 90% by weight of other thermoplastic resin; and (D) from 0 to 20 parts by weight of at least one modifier selected from a carboxylic acid having at least 2 carboxyl groups in the molecule or a derivative thereof, an amine containing at least 2 nitrogen atom in the molecular, urea or a derivative thereof, and a low-molecular weight polyamide. A coating method of a polyamide resin composition molded article is also disclosed, comprising, after bringing the surface of a resin composition molded article into contact with water, coating the surface with a coating composition.

Since polyamide resins have excellent properties in heat resistance, rigidity, strength, oil resistance, coating properties, etc., they have widely been used in the fields of automobile parts, electrical and electronic parts as engineering resins. However, the polyamide resins not only involve difficulties and points to be improved in moldability, impact resistance, water resistance, and chemical resistance but also have a high specific gravity and are high in production cost as compared with, for example, polyolefin resins.
In order to improve these drawbacks, a thermoplastic resin composition having a good balance among physical properties such as moldability, rigidity, heat resistance, impact resistance, scratch resistance, oil resistance, chemical resistance, and water resistance and being excellent in uniformity of the appearance and smoothness, formed from polypropylene and a polyamide resin, the both of which are essentially incompatible with each other, by blending an epoxy group-containing copolymer with a polypropylene resin selected from modified polypropylene and a modified polypropylene/polypropylene composition and a polyamide resin to disperse them with good compatibility, is proposed as described, for example, in JP-A-61-64741 (the term "JP-A" as used herein means an "unexamined published Japanese patent application"). However, compositions obtained by blending such a polyamide resin with other resins such as polypropylene resins are not always satisfactory because the coating properties, adhesiveness, and printability which are excellent characteristic features inherent to the polyamide resin are likely lowered. Thus, such a defect is a hindrance in developing new practical applications.
On the other hand, in order to improve the compatibility between a resin having inferior coating properties and a coating composition, a single primer layer is usually used as an interlayer therebetween. However, since not only the cost of the final product is increased owing to a high cost of the primer itself and the addition of one new step, but also an environmental problem is provided by the treatment of the waste solution of the primer, etc., a further improvement has been desired.
Moreover, it is usually practiced well to wash the surface of a resin article with a vapor of a halogenated hydrocarbon solvent such as 1,1,1,-trichloroethane before coating a primer. However, the use of 1,1,1-trichloroethane is being restricted by the ozone problem which is one of the recent environmental measures of the earth.
As a surface pre-treatment for carrying out coating, printing, adhesion, etc., a sand blast treatment, a chromic acid mixture treatment, a corona discharge treatment, a plasma treatment, a surface functional group-imparting method, a surface photografting method, etc., are proposed. However, satisfactory results are not yet obtained in any of these methods from the standpoints of environment, performance, etc.
As described above, the resin composition containing a polyamide involves difficulties in the coating properties, and the use of a primer and the surface pre-treatment for improving the coating properties have various problems from the standpoints of environment, coating performance, etc. Accordingly, the development of resin compositions containing a polyamide, to which coating, adhesion, printing, etc. can be applied well without need of the above-described surface pretreatment step, has become a large technical theme.

Surface treatment method and coating method of polyamide resin molded articles


A throttle valve controller for an internal combustion engine has a throttle valve driven by a motor. The target opening of the throttle valve is determined based on the operating state of the vehicle or internal combustion engine. A first lower limit is determined beforehand as the minimum target opening, and a second lower limit is set which is smaller than the first lower limit if the determined target opening is smaller than a predetermined opening and/or if the rotation speed of the internal combustion engine is lower than a predetermined speed.

1. Field of the Invention
The present invention relates to a throttle valve controller for internal combustion engines.
2. Description of the Related Art
In JP-A-8-74639, a technique is described which uses two closing limiters when fully closing a throttle valve. Namely, after the opening of the throttle valve is reduced to a first lower limit which is set a little higher than a second lower limit set as the target degree of opening, the throttle valve is closed to the second limit at a certain speed.

Throttle valve controller for internal combustion engine


A method of polymerizing olefins comprising combining in one embodiment ethylene and optionally one or more α-olefins with a catalyst composition in a continuous polymerization reactor at a pressure of less than 10,000 kPa; wherein the catalyst composition comprises a hafnocene; and isolating a polyethylene having a density in the range of from 0.930 to 0.975 g/cm3. Also provided is a method of transitioning a continuous polymerization reactor from production of a low density polyethylene to a medium or high density polyethylene. Also provided is a medium to high density polyethylene suitable for injection or rotomolding applications. Also provided is a single catalyst composition suitable for such needs.

The most studied metallocenes to date are titanium and zirconium based mono- and bis-cyclopentadienyl metallocenes. These catalysts, in particular, zirconocenes, are known to produce low density polyethylenes—those having a density of about less than 0.930 g/cm3—at an advantageously high activity under many types of reactor conditions. However, it is known that the most studied metallocenes to date do not produce higher density polyethylenes—those whose density is above 0.930 g/cm3—at a productivity that is commercially acceptable. See, e.g., 1 METALLOCENE-BASED POLYOLEFINS 12–14 (J. Scheirs & W. Kaminsky, eds., John Wiley & Sons 2000). Furthermore, it is known that hydrogen reduces the productivity of most metallocenes. See, e.g., J. B. P. Soares and A. E. Hamielec in 3(2) POLYMER REACTION ENGINEERING 131–200 (1995). This is a disadvantage in that hydrogen is useful (and most often necessary) for increasing the melt index (I2) of the polyethylene being produced, higher I2 (e.g., 5–50 dg/min) resins being desirable for such applications as rotomolding and injection molding products. It is also a disadvantage in that it would be desirable to use the same catalyst composition when transitioning between high, medium and low density polyethylene products in a single or multiple reactor(s), and avoiding the current need of having to change catalyst composition in order to achieve different resin products.
Metallocene derived resins have many advantageous properties that provide commercially attractive products. What would be desirable is a metallocene catalyst composition that is capable of producing medium and high density polyethylenes at commercially attractive productivities, especially polyethylenes useful in rotomolding and injection molding applications. Further, it would be useful to provide a metallocene that is capable of being used to produce a wide melt index and wide density range of polyethylene resins at commercially attractive productivities. The inventors here have discovered such a catalyst composition and process for producing these resins.

Single catalyst low, medium and high density polyethylenes


An extension tool is provided for operating handwheels, such as those found on locomotive handbrakes. The tool includes a spinning handle and a tool body. The handle freely rotates about a longitudinal axis and provides a user with a spinning grip, allowing him or her to quickly and easily turn a handwheel. The tool body includes two or more jaws that clamp to the handwheel. The tool body additionally includes a screw mechanism for selectively tightening or releasing the jaws, in order to respectively attach or detach the tool from the handwheel as desired. Preferably, the screw mechanism further includes a drawbar that extends through an interior of the handle, and is adapted to move longitudinally to rotate the jaws. The drawbar is moved by rotating a threaded drawbar nut at an end of the tool.

This invention relates to the field of tools used in the railroad industry by locomotive engineers to aid in the application release of locomotive engine vertical handwheel handbrakes. The operation of locomotive handbrakes is, in principle, the same as the handbrakes used on railroad cars. Application of the brakes means to set the handbrake to a "stop" position in which the locomotive will not move accidentally. Release of the brake means to set the handbrake to an "off" position in which the locomotive can be safely moved.
Locomotive handbrakes are placed on locomotives to be used in addition to the locomotive air brakes to keep the locomotives from moving while not in use, should the locomotive air brakes fail or be accidentally released by mistake. Handbrakes on locomotives are always left in the applied position when not being used.
One brake application release tool is shown in U.S. patent application Ser. No. 13/025,880, filed on Feb. 11, 2011. The tool is used for the application release of handbrakes on railroad freight and passenger cars. Where railroad car handbrakes are mounted on either the end or side of the car, the handbrakes on locomotive engines are typically mounted on the side of the locomotive engine compartment. The handbrake is operated from the locomotive walkway that extends the length of the engine compartment, from the rear of the locomotive to the locomotive cab. The handbrake is located so that the engineer or worker operates the brake at about waist or chest level relative to the handbrake wheel.
The handbrakes in both railroad cars and locomotives include a handbrake chain that tightens as the handbrake is applied by rotating the handbrake wheel. The biggest difference between handbrakes on railroad cars and handbrakes on locomotives is the amount of free slack in the handbrake chain. On railroad car handbrakes, this free slack is eliminated by about 2 to 4 revolutions of the wheel. However, in locomotive handbrakes, free slack is about 20 to 25 complete revolutions of the wheel. The handbrake must also be released completely when not in use, which requires reversing the process of setting the handbrake entirely. That is, turning the handwheel all the way until there is slack in the chain and the brake is fully released.
To begin the process of applying or releasing a locomotive handbrake, a railroad worker stands on the compartment walkway and grasps the handwheel with one or two hands. The worker then turns the handle in the clockwise direction to apply the brake, or in the counterclockwise direction to release the brake. This process may require the worker to re-grasp the wheel two to three times to complete one revolution of the handbrake wheel. Some operators may place two or three fingers at the junction of the handwheel inside rim and spoke, and rotate the handwheel continuously until all free slack is removed. Then, the worker grasps the handwheel at the highest point with one or both hands and fully applies the handbrake.
By trying to spin the handwheel with two or three fingers, an unsafe condition is created if the handwheel should suddenly stop and lock up. Some wheels offer continuous resistance to free spinning, and require too much force to utilize this method. This situation could also result in serious injury to the railroad worker's fingers. Therefore, a need exists for safe and effective tools for any railroad worker to remove the free slack in a handbrake chain.
Most new locomotives purchased by railroads around the time of filing, and those purchased in the prior decade, contain computers that monitor all aspects of the locomotive. These computers have sensors that trip an alarm should the handbrake not be completely released and someone tries to move the locomotive. Consequently, the handbrake handwheel must be rotated in the counterclockwise direction until it stops, and must be left in that position, in order for the locomotive computer to not trip the handbrake set alarm.
Should the locomotive handbrake handwheels have a permanently mounted handgrip on the handwheel, the handgrip would create a tripping or impact hazard, because it would be sticking out into the walking path of the railroad employee. Even if the handgrip were made to fold out of the way of the walking path, the handgrip could still become a tripping hazard due to bad maintenance or being accidentally left unfolded. The tripping hazard of a permanently mounted handgrip is increased by the fact that a high percentage of the times these walkways are traversed, they are done so at night and while the train is moving.


A method for obtaining a secure key is provided. The method includes sending an Access Safety Management Entity Key (KASME) to a gateway after finishing authentication and security process by a Mobility Management Entity (MME) in a core network; and computing, by the gateway, a Next Hop (NH) according to the KASME. The method provides a method for ensuring a working of a secure key chain when a handover process is terminated at a Hybrid Evolved NodeB Gateway (HeNB GW). Thus, key information cannot be lost when the handover process is terminated at the HeNB GW, and an impact of the handover process on a core network is reduced, and the efficiency of a User Equipment (UE) handover is improved.

1. Field of the Invention
The present invention relates to mobile communication technologies. More particularly, the present invention relates to a method for obtaining a secure key.
2. Background of the Invention
In conventional mobile communication systems, in order to provide better services to a user group, a Closed Subscriber Group (CSG) should be formed with multiple wireless resource management entities for a specific user group. The wireless resource entities may include network entities in the wireless access network for managing wireless resources and access of the User Equipment (UE) and the network entities may include base stations or cells in various mobile communication systems. For instance, all users of a corporation or a school belong to a specific user group, and for the user group, a CSG is formed with multiple wireless resource management entities for providing special access services. For a specific user group, it is a common that the CSG is formed with multiple wireless resource management entities. A description is given hereafter using a Long Term Evolution (LTE) system of a System Architecture Evolution (SAE) as an example.
FIG. 1 is a schematic diagram illustrating a structure of an LTE system according to the related art.
Referring to FIG. 1, in a wireless access network of the LTE system, wireless resource management entities include Evolved NodeBs (eNBs) 102 and Home Evolved NodeBs (HeNBs) 103, and may further include a HeNB Gateway (HeNB GW) 104, as required. The eNB may directly connect with the Mobility Management Entity (MME) 105 in a core network. When the wireless resource management entity includes a HeNB GW 104, the HeNB 103 should connect with the MME 105 through the HeNB GW 104. When the wireless resource management entity does not include the HeNB GW 104, the HeNB 103 may directly connect from the MME 105.
In order to provide more access services in conventional mobile communication systems, various types of HeNBs, such as open HeNBs, hybrid HeNBs, and CSG HeNBs are provided. The open HeNBs do not have a specific user group which accesses the open HeNBs, and thus, any UE can access to the open HeNBs. The CSG HeNBs are used by a specific user group, such as all users in the above noted corporation and school. The CSG HeNBs are accessed by the UEs of the specific user group, which are referred to as CSG UEs, wherein the specific user group is served by the CSG HeNBs. The hybrid HeNB forms itself and other HeNBs into a CSG user group in order to provide access to the CSG UEs served by itself in order to provide better access services to the CSG UEs. Additionally, the hybrid HeNBs also allow the access of other non-CSG UEs, which are UEs not belonging to the CSG.
According to the above description, the conventional mobile communication system includes a CSG formed with multiple wireless resource management entities for providing CSG wireless resource management entities, such as CSG HeNB. The conventional mobile communication system also includes hybrid wireless resource management entities, such as hybrid HeNBs, for providing more access services. At the same time, the eNB may also support the functions of the CSG, or may be used as a hybrid eNB while supporting the CSG functions.
FIG. 2 is a schematic diagram illustrating a handover process for a UE moving between HeNBs or eNBs according to the related art.
Referring to FIG. 2, the movement of the UE is implemented through an S1 handover process. As shown in FIG. 2, optional descriptions of the S1 handover process which are well known to those skilled in the art are omitted in the following descriptions. The S1 handover process mainly includes the fowling processes. In step 201, a Source-(H)eNB (S-(H)eNB) sends a handover required message to a HeNB GW. The HeNB GW sends the handover required message to the MME in step 202. Next, the MME sends a handover request message to the HeNB GW, and the HeNB GW sends the handover request message to a Target-(H)eNB (T-(H)eNB) in step 203. In step 204, the T-(H)eNB allocates resources, sends a handover request acknowledgement message to the HeNB GW, and the HeNB GW sends the handover request acknowledgement message to the MME.
In step 205, the MME sends a handover command message to the HeNB GW, and the HeNB GW sends the handover command message to the S-(H)eNB. The S-(H)eNB sends the handover command message to the UE in step 206. In step 207, the UE synchronizes itself to a target cell, and sends a handover acknowledgement message to the T-(H)eNB. Next, the T-(H)eNB sends a handover notification message to the HeNB GW, and the HeNB GW sends the handover notification message to the MME in step 208. Then, the MME sends an update bearer request message to a Service-Gateway (S-GW)/Packet Data Network Gateway (PDN GW) in step 209. For convenience of description, the signaling processes between the S-GW and the PDN GW are omitted. The S-GW mainly provides a function of a user plane and the PDN GW is responsible for the charging, legal monitoring, and other similar functions. According to information of the UE's contexts, if the PDN GW has requested for the UE location and/or user CSG information, the MME carries information elements of the UE location and user CSG information in the update bearer request message.
Next, in step 210, the S-GW/PDN GW sends the update bearer response message to the MME. The UE initiates the Tuning and Analysis Utility (TAU) process in step 211. In step 212, the MME sends a UE context release command message to the HeNB GW, and the HeNB GW sends the UE context release command message to the S-(H)eNB. In step 213, the S-(H)eNB sends a UE context release completion message to the HeNB GW, and the HeNB GW sends the UE context release completion message to the MME.
It should be noted that the S-(H)eNB and the T-(H)eNB in FIG. 2 may be a HeNB or an eNB because the above process also applies in the S1 handover when the UE moves between the eNBs. Thus, S-eNB denotes a Source-eNB, T-eNB denotes a Target-eNB, S-HeNB denotes the Source-HeNB, and T-HeNB denotes the Target-HeNB.
It can be seen that when there are many HeNBs or eNBs, if the above handover method is adopted and each time the UE switches between the HeNB and eNB through the S1 handover, there is a very heavy load on the core network, and the many HeNBs or eNBs reduce an efficiency of the handover made by the UE under the same HeNB GW. Under this circumstance, if the handover process of the UE terminates at the gateway, the load brought on the core network by the handover may be reduced greatly. However, the communication protocol in the conventional standard does not advance a detailed solution wherein the handover process ends at the gateway. On the other hand, a security mechanism in the conventional standard also cannot allow the handover which terminates at the gateway.
FIG. 3 is a schematic diagram illustrating a structure of encryption secure levels in an Evolved-Universal Mobile Telecommunication Systems (UMTS) Terrestrial Radio Access Network E-UTRAN according to the related art.
Referring to FIG. 3, K is a permanent key of a universal integrated circuit card on a Universal Subscriber Identity Module (USIM) and an Authentication Center (AuC). A Cipher Key (CK) and an Integrity Key (IK) are generated by the AuC and the USIM in a process of Authentication and Key Agreement (AKA). The CK and IK are processed differently in an Evolved Packet System (EPS) services and the legacy secure contexts.
An Access Safety Management Entity Key (KASME) is an intermediate key generated by the UE and MME after the AKA. The UE and MME further generate the key for the Non-Access Stratum (NAS) Layer Encryption (KNASenc) and NAS Integrity Protection (KNASint) according to the KASME. The Evolution Node Key (KeNB) is a key obtained by the UE and the MME or by the UE and the eNB. A Next Hop (NH) is a key for the forward secure derived by the UE and the MME. A key KUPenc for encrypting an air interface access layer user plane, a key KRRCenc for controlling a plane encryption, and a key KRRCint for controlling a plane integrity protection are further derived according to the KeNB.
FIG. 4 is a schematic diagram illustrating the principle for generating the key during the handover process according to the related art.
Referring to FIG. 4, the initial KeNB is calculated according to the KASME and a NAS uplink COUNT. When the UE and eNB need to establish the initial Access Stratum (AS) secure contexts, the KeNB and the NH are derived by the MME and UE. The KeNB and NH are derived from the KASME. A NH Changing Counter (NCC) of the NH is associated with each KeNB and NH. Each KeNB is associated with the NCC corresponding to the NH, and from which the KeNB is derived. At the beginning, the KeNB is directly derived from the KASME. Thus, the KeNB is associated with a virtual NH, and the NCC, to which the NH corresponds, is 0. At the beginning of the establishment, the derived NH corresponds to the NCC 1. The initial NCC is 0 when the eNB receives the initial contexts establishment request.
In the process of a handover, the eNB key used between the UE and the target eNB is derived from the current eNB or NH. In order to distinguish the eNB key used between the UE and the source NB and the eNB key used between the UE and the target NB, the former is recorded as KeNB, and the latter is recorded as the KeNB*. A method for deriving the key according to the current KeNB is called the horizontal key generation mechanism, and a method for deriving the key according to the NH is called the vertical key generation mechanism. When the KeNB* is generated according to the KeNB or NH, the Physical Cell Identity (PCI) and frequency (EARFCN-DL) of the target cell should be bound.
It can be seen that only the UE and the MME can compute the current NH, and the gateway does not have the ability of computing the current NH. Thus, if the handover terminates at the gateway, the gateway cannot obtain the current NH. Accordingly, the conventional method of communication discussed above has many disadvantages in security. Thus, the conventional method does not solve the problem of ensuring the working of a secure key chain when the handover terminates at the gateway.

Method and system for positioning mobile station in handover procedure


A method of limiting access to network sites for a network kiosk which controls public operation of the kiosk. The method includes the steps of receiving a request to display the web page by the kiosk, determining an address of the web page, determining a current time, determining an unacceptable period of access to the web page, and preventing access to the web page if current time falls within the unacceptable period.

The present invention relates to self-service kiosks and more specifically to a method of limiting access to network sites for a network kiosk.
Retailers have a desire to sell their products over networks, such as global networks which are a part of the World Wide Web (WWW or "web") and which use the Transmission Control Protocol/Internet Protocol (TCP/IP protocol). These retailers wish to provide Internet server web sites which offer the same features as Internet server web sites available to home shoppers who use their computers to connect to the Internet server web sites.
Kiosks provide a publicly-accessible computing platform for displaying web pages from retailer web sites. Kiosks may be located within a retailer's transaction establishment or elsewhere, such as in shopping malls. Kiosks may be easily networked to retailer web sites using the TCP/IP protocol. Web pages from web sites may be displayed using known and available web software, such as Microsoft® Internet Explorer software.
One problem with allowing the general public to use a network kiosk is that an operator may choose not to visit web sites of the kiosk owner, thereby making the network kiosk less effective in promoting goods and services offered by the kiosk owner. However, if the kiosk owner were to prohibit any use of the network kiosk to access non-owner sites, use of the network kiosk would be less attractive to the general public and public use would fall off. Also, current methods of limiting access or "filtering" web site addresses used by web browser applications are not flexible enough to accommodate scheduled changes in access.
Therefore, it would be desirable to provide a method of limiting access to network sites for a network kiosk which makes the network kiosk attractive to both kiosk owners and to operators from the general public.

Method of limiting access to network sites for a network kiosk