Showing papers by "NTT DoCoMo published in 1999"

High sensitivity radio receiver

Abstract: The invention relates to a high sensitivity receiver installed outdoors which may be used in a base station of a mobile communication system, for example. A received radio frequency signal is converted into a signal in a desired frequency band by a reception bandpass filter RXF3, is subject to a low noise amplification to a desired level by a low noise reception amplifier LNA4, and the amplified signal is converted into an optical signal by a laser diode LD5. RXF3, LNA4 and LD5 are confined in a heat shielding box. LD5 is cooled by cooling means to the order of critical temperature where RXF3, for example, assumes a superconducting state, whereby the dynamic range is increased and stabilized.

Charging method for information communication network

Abstract: When a mobile accesses an IP (information provider), a gateway server judges whether or not the IP server is an object of information provider charging (S101). If not, the gateway server applies a user charging to the IP server, and transmits to a charging system the user management number of the mobile and the number of packets sent and received (S102). The charging system calculates the communication charge corresponding to the number of packets and issues a bill to the user specified by the user management number (S103). If the IP server is an object of an information provider charging, the gateway server applies the information provider charging to the IP server, and transmits to the charging system the number of packets sent and received and the address of the IP server (S104). The charging system calculates the communication charge corresponding to the number of packets and issues a bill to the IP (S105).

Whisper: a wristwatch style wearable handset

Abstract: Whisper is a new wrist-worn handset, which is used by inserting the fingertip into the ear canal. A received signal is conveyed from a wrist-mounted actuator to the ear canal via the hand and a finger by bone conduction. The users voice is captured by a microphone mounted on the inside of the wrist. All components of Whisper can be mounted on the wrist, and usability does not de- crease if the size of components is miniaturized. So, both wearability and usability can be achieved together. The way Whisper is operated is similar to that of an ordinary telephone handset. Thus, onlookers may not look upon Whispers operation as talking to oneself, even if the associated PDA is controlled by voice commands. Whis- per is especially effective in a noisy environment. Signals received via bone conduction can be heard clearly in the presence of noise without raising the volume (-12 dB at noise = 90 dB(A) in comparison to cellular phone hand- set). Whisper is also effective in avoiding the annoying problem of the users voice being raised in a noisy situa- tion. Feedback of the users utterance is boosted by bone conduction when covering the ear canal with a fingertip, then the users voice does not need to raised in the pres- ence of noise (-6 dB at noise = 90 dB(A) in comparison to cellular phone handset). Whisper is useful as a voice interface for a wrist-worn PDA and cellular phone.

Communication system for mobile devices

Abstract: The present invention has the purpose of providing technology capable of efficiently transmitting data when performing data communications between a mobile station and a server apparatus. A simplified protocol TL is employed on the transport layer instead of TCP/IP. The simplified protocol TL is used as the communication protocol on a wireless communication path (radio-oriented interval) between an MS (Mobile Station) 1 and a GWS (GateWay Server) 5. The simplified TL protocol is utilized to relay data communications between the MS 1 and a CPS 8 (Content Provider Server). The response of data communications is therefore improved by a decrease in traffic between the MS 1 and the GWS 5 and reduction in overhead in comparison to when TCP/IP is deployed. As a result, the user can efficiently access content provided by the CPS 8 over the Internet via a wireless communication path. Efficient access may occur even where the wireless communication path has low data transmission capacity in comparison to a wireline communication path. In addition, efficient access may occur where the user is using an MS 1 which has insufficient data processing power to deploy TCP/IP.

CDMA receiver and CDMA transmitter/receiver

Abstract: A CDMA receiver and a CDMA transmitter/receiver, which are less sensitive to fading and capable of accurate channel estimation while taking into consideration the rate of channel changes When channel estimation is performed by summing the weights on the pilot symbol (average) inserted in a data symbol sequence, the rate of channel changes is taken into consideration for the weighting control For instance, the inner product value of the channel estimate and the pilot symbol (average) is used as an update value for weighting control This results in accurate channel estimation

Interference avoidance radio communications system

Abstract: A base station 422 of a second system performs communication using a frequency adjacent to a frequency employed by communication between a base station 412 and a mobile station 414 of a first system. When the mobile station 414 is close to the base station 422, the communication of the base station 422 undergoes interference by the leakage power of the mobile station 414. To avoid the interference, the transmission is halted of the mobile station 414 of the first system, which provides the interference by the leakage power.

Communication channel selecting method and base station device

Abstract: A decision is made as to whether a radio base station acting as an interference source is present in a macrocell or microcell, so that the interference from a mobile station transmitting high power can be presented in advance. The base station inserts its transmission power value of a forward broadcast channel into broadcast information. A newly installed base station C, receiving a forward frequency band, measures the received level of the broadcast channel, and captures the transmission power value. When the transmission power value is large, the threshold value is reduced (THRb), and when the transmission power value is small, the threshold value is increased (THRa). If the received level L is less than the threshold value, a decision is made that the channel is available.

Traffic control method for mobile data communication, mobile station device and base station device

Abstract: A traffic control method for mobile data communication capable of enhancing the communication quality of a mobile communication system using diffusion signals such as CDMA and effectively utilizing a radio frequency in use, a base station device, and a mobile station device. A mobile communication system using diffusion signals including CDMA, which is provided with two kinds of communication channels, a common channel and a plurality of individual channels, and is so designed that the common channel is used by a plurality of contending users and each of individual channels is dedicated to one user, wherein the common channel and the individual channels are used for communication between mobile radios and a radio base station and, during the communication, the radio base station or a mobile radio receives and judges a transfer from the common channel to an individual channel when the communication traffic of a mobile radio is being transferred from a coarse status to a dense status.

Communication control system, communication method, server device, terminal, relay device, and communication system

Abstract: A technique capable of efficiently transmitting data when data communication is made between a mobile station and a server device. As a communication protocol in a radio-system section from GWS (GateWay Server) (5) to MS (mobile station) (l) for relaying data communication between MS (1) and CPS (Contents Provider Server) (8), there is employed TL, which is a simplified protocol in transport layers, in place of TCP/IP, whereby, as compared with the case of employing TCP/IP, the traffic between MS (1) and GWS (5) decreases, so does overhead, and response during the data communication is improved. As a result, the contents provided by CPS (8) on the Internet can be comfortably utilized through the radio-system section that is low in data transfer capability.

Location Oriented Integration of Internet Information - Mobile Info Search

Abstract: Information on the Internet is becoming more attractive and useful for our daily life. It provides things on the town, happenings on the city, and learning of the real world. If we can utilize such information for the interaction between the human and the city, it can enhance the value and the function of the city. In this paper we introduce the research project "Mobile Info Search" in which we study the method of integrating heterogeneous information in a location-oriented way for providing it in a handy form with mobile computing. We have a prototype of Mobile Info Search at http://www.kokono.net/, a location-based "search engine". Local information such as yellow pages, maps, and relevant Web pages at any location of Japan are provided with a simple interface. From the analysis of test services, we will discuss the user issues and information source issues; What kind of local information is welcomed? What can we learn from collected documents? Through the experience of handling various contents related to the real-world, we describe the potential of the Internet information for the digital city efforts.

Push information delivery method and its repeater

Abstract: The user of a mobile ready to receive information providing service from a nonspecific IP (information provider) server accesses a gateway server and carries out registration (S71). The IP server writes an electronic mail including the information to be provided to the user if it has the information, adds the attribute data on the user to the electronic mail, and sends the electronic mail to the gateway server (S72). On receiving the electronic mail, the gateway server stores the electronic mail in a third mailbox, checks the user attributes, and calls the user's mobile (S73). The called user requests the gateway server to download the electronic mail (S74). The gateway server sends the electronic mail to the mobile having made the request (S75, S76).

Bandwidth control method of packet data in packet switching network and packet switching network system

Abstract: Efficient use of an ATM transmission path becomes possible by multiplexing, into a bandwidth in the bandwidth-assured individual VP, a plurality of users whose traffic volumes are beyond a predetermined value. Installing a bandwidth-unassured common VP for low traffic users makes it possible to switch from the common VP to the individual VP or vice versa under the following conditions. (1) When the user traffic volume, monitored at fixed intervals during the communications through an individual VP, drops below a predetermined threshold value, the individual VP is switched to a common VP. (2) When the user traffic volume, monitored at fixed intervals during the communications through a common VP, exceeds a predetermined threshold value, the common VP is switched to an individual VP. (3) In addition to condition (2), when bandwidth shortage takes place in common VPs, the common VPs of heavy traffic users are switched to individual VPs.

Cluster configuration mobile communication system, mobile station, cluster control station, line control station and mobile station

Abstract: PROBLEM TO BE SOLVED: To provide an efficient mobile communication network through the autonomous distribution processing of a base station by enhancing the communication quality and relieving a load of a line control station and a load between the base station and the line control station onto a channel. SOLUTION: A mobile station 20 is connected to other exchange station or the internet via a base station 31, a cluster control station 21, a line control station 40, and a mobile communication exchange station 13. Cluster control stations 21, 22 distribute a signal from the line control station 40 to base stations 31, 32 and synthesizes incoming signals from each base station and the same mobile station and transmits the synthesized incoming signal to the line control station 40. Each base station receives an outgoing signal from the cluster control stations 21, 22 or other base station that is addressed to itself or required for itself only. Furthermore, each base station relays the outgoing signal to other base station as required. The mobile station 20 transmits/receives a wireless signal simultaneously to a plurality of adjacent base stations (in Figure, base stations 311, 312, 313). COPYRIGHT: (C)2001,JPO

Packet transmission method, packet transmission system and packet data transmission medium on mobile communications network system

Abstract: An address structure in mobile communications network facilitating routing of a packet. At the initial position of the address, is located a prefix or the like indicating the type of the address structure, which indicates the present mobile communications network system, for example. At the next position, a location address (LA) is located characterizing the present invention. The location address is usually placed at the position of a subnetwork address. The location address (LA) is provided for each mobile switching system, and constitutes part of an IP address of a user using a mobile station under the control of the mobile switching system. At the final position, is located a user identifier (user ID) which is used for identifying a user, and is provided uniquely for each user. The IP address in accordance with the present invention can be split into the foregoing three sections, part of which includes the location address and user identifier indicating the location of the mobile station in the mobile communications network, thereby enabling the identification of the user in the mobile communications network system and the control of the packet transmission.

Interference-free radio communication system

Abstract: A base station (412) and a mobile station (414) in a first system communicate at a frequency adjacent to that used for a base station (422) to communicate in a second system. When the mobile station (414) is near the base station (422), the base station (422) is affected by interference due to the leakage power from the mobile station (414). To prevent this interference, the transmission of the mobile station (414) causing the interference is stopped in the first system.

Assignment method for channel identifier and mobile communication system

Abstract: PROBLEM TO BE SOLVED: To reduce complicatedness in design and management of a mobile communication system by decreasing power consumption and time required for a mobile station to search for peripheral cells. SOLUTION: The method of this invention searches for peripheral cells by utilizing information given to a mobile station from a sector in the mobile communication system the mobile station decides a standby sector or a communication sector for making communication with mobile stations by using grouped channel identifiers received from sectors, and includes a step where a channel identifier belonging to the same group is assigned to sectors in the same base station and a step where a base station informs the mobile station in zone in the base station about any of channel identifiers assigned to sectors of one peripheral base station.

Error protection method and error protection device

Abstract: The frame-forming data computing part 101 sorts a plurality of types of parameters forming the frames, and generates frame-forming data that contains data relating to the configuration of said frames and data establishing for each class the error protection method to be applied to each said parameter. The frame-forming data error protection processing part 102 implements the specified error protection for said frame-forming data. The class data error protection processing part 103 implements error protection that is specified for each class according to the frame-forming data, with respect to the parameters that are sorted into a plurality of classes. The synthesizer 104 transmits the frame-forming data that has undergone the specified error protection and the parameters that have undergone the error protection established for each class. In accordance with the present invention, error correction is implemented on frame-forming data indicating the configuration of the frames, and it is also implemented on each class according to the frame-forming data, and these two are synthesized and output. Therefore, it becomes possible to obtain data relating to the configuration of said frames, according to frame-forming data received by the receiving side device. As a result, it is possible to set on the transmission side as desired the content of the error protection to be applied to each class, and in addition, error protection becomes possible for each frame, due to the fact that these data are contained in the frame-forming data, even if the frame has a variable frame length, with the number of bits fluctuating over time.

Method for assigning time slot

Abstract: PROBLEM TO BE SOLVED: To provide a method for assigning time slot by which many information sets are trasnsmitted at a high-speed in a mobile communication system in the times of multimedia and the transmission quality corresponding to needs can be provided. SOLUTION: A plurality of time slots is assigned to cells T1-T7 and the number of time slots assigned to each of the cells T1-T7 is made variable. The time slot is assigned depending on the traffic of the cells T1-T7 and/or the quality of service QoS of a user. Or, on the occurrence of a call, the utilizing state of the time slot of cells in a range of causing interference is referenced and a time slot not used in cells in the range of causing interference may be assigned. COPYRIGHT: (C)2001,JPO

Error protecting method and error protective device

Abstract: Parameters representing the coding rate, the number of bits of an error detection code, the presence/absence of interleave, and so forth, which are conditions under which an audio signal is compressed, coded, and transmitted, are classified by an error protecting method to be applied so as to achieve suitable error protection.

Method and apparatus for communication control, and recording medium

Abstract: When a disconnection occurs in a telecommunication line, a communication control module tries a reconnection without notifying a communication module of the trouble if the connection is considered resumable. The telecommunication line may be reconnected, for instance, if the disconnection is temporary or if the network conditions are good. When the telecommunication line has been reconnected, the communication module does not notice the disconnection of the telecommunication line. After that, therefore, the communication module resumes the data communication in the same manner as before.

Broadcast communication method, mobile communication system using the communication method, and mobile station

Abstract: PROBLEM TO BE SOLVED: To attain broadcast communication with high efficiency and high reliability by instructing the mobile station that received no broadcast communication to make inquiries to a base station network among plural mobile stations SOLUTION: In a step 1, a base station network transmits the information (program lists) including the broadcast communication times, group numbers, etc, to plural mobile stations of object groups of the broadcast communication In a step 2, the base station network carries out the broadcast communication according to the program lists which are previously transmitted A mobile station that could not receive the broadcast communication gives a retransmission request to the base station network in a step 3 Receiving the retransmission request, the base station network retransmits the contents of the broadcast communication to the mobile station in a step 4 In a step 5, the base station network can transmit once or several times the information showing execution of the broadcast communication to the mobile stations of groups of streets COPYRIGHT: (C)2001,JPO

Traffic channel selecting method and base station equipment

Abstract: A decision is made as to whether a radio base station acting as an interference source is present in a macrocell or microcell, so that the interference from a mobile station transmitting at high power can be prevented in advance. The base station inserts its transmission power value of a forward broadcast channel into broadcast information. A newly installed base station C, receiving a forward frequency band, measures the received level of the broadcast channel, and captures the transmitted power value. A propagation loss is calculated from the received level of the broadcast channel and the transmission power value acquired, and a decision is made that the channel is available, if the propagation loss is less than a certain value, and the received level is less than the threshold value.

Path timing detection method of mobile communication system and base station device

Abstract: PROBLEM TO BE SOLVED: To improve the path timing detection accuracy and also to suppress the increase of processing load in a random access mode of a mobile communication system. SOLUTION: An effective path timing range is identified by means of a preamble A and then the effective path timing is detected out of the identified path timing range when a message C is received. Thus, the path timing is detected with high accuracy compared with a conventional case where a path is detected only by a preamble. Furthermore, a search range is identified when the preamble A is received to reduce the processing load compared with a case where the path timing is detected out of all search ranges accordant with the cell radii. COPYRIGHT: (C)2001,JPO

Interference avoidance in radio communication systems

Abstract: A base station 422 of a second system performs communication using a frequency adjacent to a frequency employed by communication between a base station 412 and a mobile station 414 of a first system When the mobile station 414 is close to the base station 422, the communication of the base station 422 undergoes interference by the leakage power of the mobile station 414 To avoid the interference, the transmission is halted of the mobile station 414 of the first system, which provides the interference by the leakage power

Push-type information transmission with user management

Abstract: The present invention relates to an information transmission method in a communication network comprising an information provider device communicating in a first network, a plurality of user terminals for receiving information provided by the information provider device communicating in a second network, and a transfer device for routing information between the information provider device and user terminals. There is registered at least a network address of a user terminal in correlation with a user management number for the user terminal. The user management number is used for identification of the user terminal only in the first communication network. The user management number has a one-to-one correspondence with the network address for the user terminal and is different from the user terminal. At the transfer device, there is received from the information provider device information supplied with designated user management number as a desired designation. Then, there is determined a network address that corresponds to the designated user management number, and at least a part of the information is transmitted to the determined network address.

Packet transmission system in mobile communications network system

Abstract: An address structure in mobile communications network facilitating routing of a packet. At the initial position of the address, is located a prefix or the like indicating the type of the address structure, which indicates the present mobile communications network system, for example. At the next position, a location address (LA) is located characterizing the present invention. The location address is usually placed at the position of a subnetwork address. The location address (LA) is provided for each mobile switching system, and constitutes part of an IP address of a user using a mobile station under the control of the mobile switching system. At the final position, is located a user identifier (user ID) which is used for identifying a user, and is provided uniquely for each user. The IP address in accordance with the present invention can be split into the foregoing three sections, part of which includes the location address and user identifier indicating the location of the mobile station in the mobile communications network, thereby enabling the identification of the user in the mobile communications network system and the control of the packet transmission.