KR20040027105A - Is-95 service network in the underground environment by using 1x ev bts - Google Patents

Abstract

PURPOSE: An IS-95 service network in an underground environment using 1xEV(Evolution) is provided to allow IS-95 subscribers to receive service in an underground environment by adding an IS-95 channel to a BTS(Base Station Transceiver Subsystem) of an 1x EV service network having good speech quality. CONSTITUTION: A base station(110) cuts off connection between a coupler(112) which couples a signal of an IS-95 BTS(114) and transmits it to an MMHS(Master Main Hub System)(118). Instead, an IS-95 service channel is added to an 1xEV BTS(116) and an optical signal transmitted to an IS-95 BTS(114) is directly transmitted to the MMHS(118) through the added channel of the 1xEV BTS(116). Signal of the IS-95 BTS(114) are all cut off and 779 channel is transmitted through the 1xEV BTS(116) dedicated for an underground. Namely, the 779 channel of the IS-95 BTS(114) is in OFF state, the 779 channel of the 1xEV BTS(116) in an ON state is transmitted to antennas(150a,150b,...,150n) through an optical cable(120), a light distributor(130) and an optical cable(140) after passing through the MMHS(118), allowing the IS-95 terminal(160) to make call communication.

Description

IS-95 SERVICE NETWORK IN THE UNDERGROUND ENVIRONMENT BY USING 1X EV BTS}

The present invention relates to a telecommunication service network, in particular to improve IS-95 service quality using the 1X EV service network to overcome the difference in call quality caused by the IS-95 and 1X EV service difference in the underground environment. It is about technology.

In general, CDMA (Code Division Multiple Access) refers to a signal transmission method between a base station and a terminal in a wireless section. Synchronous CDMA mobile communication uses CMDAOne and IMT-2000 including the IS-95 standard CDMA standard according to the wireless section protocol. For CDMA2000, including IS-2000.

CDMA200 currently implements 1X EV (Evolution) service. 1X EV is based on the High Data Rate (HDR) protocol, which is a high-speed packet data method.It is 1X EV-DO (Data Only) that transmits only data, and 1X EV-DV (Data and Voice) that simultaneously transmits voice and data. ).

Currently, mobile operators are providing mobile communication services in the basement rather than on the ground. If the mobile communication terminal is for IS-95 or 1X EV service, a mobile communication service network is established.

1 is a configuration diagram of a service network for implementing IS-95 and 1X EV services in an underground environment according to the prior art.

Referring to FIG. 1, a mobile communication service network in an underground environment includes an optical repeater 10, a base station device 20, optical cables 30 and 50, an optical dispersion device 40, antennas 60a, 60b,. 60n), IS-95 terminal 70, and 1X EV terminal 80. Here, the base station 20 is composed of a coupler 22, a base station transceiver subsystem (BTS) 24 for the IS-95, a BTS 26 for the 1X EV, and a hub system (MMHS: Master Main Hub System, 28). Meanwhile, in order to distinguish terminal services, the terminal 160 for IS-95 and the antennas 150a, 150b, ... 150n are 95A, and the 1X EV terminal 17 and the antennas 150a, 150b, ... 150n are shown in FIG. ) Is abbreviated as 1X.

The mobile communication service network in the underground environment configured as described above provides mobile communication services to the IS-95 and 1X EV terminals 70 and 80, respectively, both of which use the optical dispersion device 40 in common. But the motherland is different.

That is, the IS-95 service network couples the RF signal transmitted from the general BTS 24 through the coupler 22 and delivers the RF signal to the hub system 28. The 1X EV service network is directly connected to the hub system 28 from the BTS 26 dedicated to the underground. The RF signal transmitted to the hub system 28 is converted into an optical signal and then transmitted to the optical dispersion device 40 through the optical cable 30, and the optical dispersion device 40 converts it into an RF signal and then returns the optical signal. After converting to a signal, the optical cable 50 is transmitted to each of the dispersing devices installed at the final stage, and then each of the IS-95 terminal 70 and the 1X EV terminal 80 through the antennas 60a, 60b, ... 60n. To pass).

However, in the related art, the IS-95 service network is a method in which the ground environment BTS 24 is connected to the optical dispersion device 40 after coupling through the coupler 22, and the 1X EV service network is a dedicated BTS 26. Since the method is directly connected to the optical dispersion apparatus 40 through the service network, a difference in communication quality occurs. In particular, the T_Adjust parameter representing the communication output between base stations in the terminal has a large difference in communication quality.

The reason for this is that in the IS-95 service network, the service in the ground environment is preferred, so the RVS (reverse) gain setting in the underground environment is set to about 7 to 10 dB lower than the ground, and in addition, the optical repeater is grounded. In this case, the RVS environment of the subway service is much worse than the 1X EV service network.

Therefore, there is a problem that the service quality of the IS-95 subscriber is degraded because the communication quality of the IS-95 service network is lower than that of the 1X EV service network in the underground environment according to the prior art.

An object of the present invention is to block the connection between the coupler and the hub system of the IS-95 service network in the underground environment in order to solve the above problems of the prior art, and instead to the BTS of the 1X EV service network having a relatively good call quality. By adding IS-95 channels, IS-95 subscribers can also be serviced through the 1X EV service network in the underground environment, improving IS-95 subscriber call quality. It is to provide a service network.

In order to achieve the above object, the present invention provides a hub system by coupling signals of an IS-95 BTS in a mobile communication service network providing an IS-95 service in an area in which an BTS for IS-95 and a BX for 1X EV are installed. Disconnects the hub system from the coupler and transmits the signal to the IS-95 terminal by adding a service channel for the IS-95 to the 1X EV BTS. It transmits to the terminal for IS-95 via a device.

1 is a configuration diagram of a service network for implementing IS-95 and 1X EV services in an underground environment according to the prior art;

2 is a block diagram showing an IS-95 and 1X EV service network in an underground environment using 1X EV according to the present invention;

3 is a view showing the IS-95 and 1X EV channel configuration in the underground environment according to the prior art,

4 is a view showing the IS-95 and 1X EV channel configuration in an underground environment according to the present invention,

5A to 5C are graphs comparing the quality of IS-95 service according to the present invention and the prior art.

<Description of the code | symbol about the principal part of drawing>

100: optical repeater 110: base station

112: Coupler 114: BTS for IS-95

116: BTS 118 for 1X EV: Hub System

120, 140: optical cable 130: optical dispersion device

150a, 150b,... 150n: antennas

160: terminal for IS-95 170: terminal for 1X EV

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

3 is a diagram illustrating an IS-95 and 1X EV service network in an underground environment using 1X EV according to the present invention.

Referring to FIG. 3, the mobile communication service network in the underground environment includes an external service antenna 100, a base station apparatus 110, optical cables 120 and 140, an optical dispersion apparatus 130, antennas 150a and 150b, ... 150n), IS-95 terminal 160 and 1X EV terminal 170. Meanwhile, in order to distinguish terminal services, the terminal 160 for IS-95 and the antennas 150a, 150b, ... 150n are 95A, and the 1X EV terminal 17 and the antennas 150a, 150b, ... 150n are shown in FIG. ) Is abbreviated as 1X.

Here, the base station 110 is composed of a coupler 112, the BTS 114 for IS-95, the BTS 116 for the 1X EV and the hub system (MMHS) 118 dedicated to the underground environment. 110 disconnects the hub system 118 from the coupler 112 that couples the signals of the BTS 114 for IS-95 and transmits them to the hub system 118. In other words, the IS-95 service network can be omitted in the underground environment. Instead, the present invention adds the IS-95 service channel to the 1X EV BTS 116 of the base station apparatus 110 and directly transmits the optical signal transmitted to the BTS 114 for IS-95. Can be delivered to hub system 118 via an added channel.

3 is a view showing the IS-95 and 1X EV channel configuration in the underground environment according to the prior art. Referring to FIG. 3, the BTS for IS-95 in the conventional underground environment uses a total of six channels of 779, 738, 697, 193, 234, and 275, and the BTS for 1X EV is 111, 152, 70, 193, A total of five channels of 316 are used. However, three of the 1X EV channels, 152, 70, and 193, are beacons, so they can be used as a call channel on the ground, but they cannot make calls in the underground environment. Therefore, beacons 152, 70, and 193 channel signals to channel 111, which is used as a call channel in the underground environment, and hands off the ground. The 316 channel, which is not described herein, is used as a channel for 1X EV data communication.

Therefore, in the present invention, by adding 779 channels for IS-95 service to the five channels for the IX EV, the IS-95 terminal can be serviced through the BX for 1X EV without going through the BTS for IS-95 in the underground environment. Can be.

4 is a diagram showing the configuration of IS-95 and 1X EV channel in the underground environment according to the present invention. Referring to FIG. 4, the present invention turns off 779 channels in all six channels used in the BTS for the IS-95 in an underground environment and beacons the remaining five channels 738, 697, 193, 234, and 275. Allow handoff with the ground. In addition, a total of five channels 111, 152, 70, 193, and 316 used in the 1X EV BTS are added to the 779 channel, which is an IS-95 service channel, to use a total of six channels. In this case, the 779 channel is used as the second channel in the 1X EV BTS because the IS-95 terminals are programmed to search for the 779 channel first, so the IS-95 terminals can search for and tune the BTS signal. It is set to 779.

Therefore, the present invention enables the IS-95 terminals to make calls through the 779 channel added in the 1X EV BTS, and the terminals in the 5 channels of the BTS for IS-95 (738, 697, 193, 234, and 275). When moving underground, beacons are handed off to the ground, 111 or 1779, the first channel of the 1X EV BTS.

The mobile communication service network in the underground environment according to the present invention configured as described above provides mobile communication services to the IS-95 and 1X EV terminals 160 and 170 using the 1X EV service network as follows.

The IS-95 service of the present invention proceeds as follows. All signals of the BTS 114 for the IS-95 are blocked and 779 channels are transmitted through the BX 116 for underground use only. That is, since the 779 channel of the IS-95 BTS 114 is in an OFF state, the 779 channel of the 1X EV BTS 116 in the ON state is transmitted, and the optical cable 120 is passed through the hub system 118. And, through the optical dispersion unit 130 and the optical cable 140 is transmitted to the antenna (150a, 150b, ... 150n) is the terminal for the IS-95 160 to make a call.

The 1X EV service in the underground environment transmits the signal transmitted to the 111 channel of the BTS 116 for 1X EV directly to the hub system 118 as in the prior art, and the optical cable 120, the optical dispersion unit 130 and the optical fiber. The cable 140 transmits the antennas 150a, 150b, ... 150n to the 1x EV terminal 170 to make a call.

5A to 5C are graphs comparing the quality of the IS-95 service according to the present invention and the prior art. Referring to these graphs and Table 1, the call quality of the IS-95 service network in the underground environment is reduced according to the present invention. It can be seen that the improvement.

division IS-95 1X EV Difference T_Adjust -8.9 -30.8 22 dB RX Power -71.7 -72.8 -1.1 dB Ec / Io -4.6 -3.6 1 dB Connection success rate 96.7 99.3 2.6% CD 5.5 1.5 4%

In Table 1, T_Adjust is a measure of the transmission power sent by the terminal to the base station, RX Power is the reception field received from the base station at the terminal, Ec / Io is the base station signal to noise ratio of the other station, and C / D is the call drop. will be.

Since the present invention receives the IS-95 channel from the 1X EV BTS, as shown in FIG. 5A, the RX power signal (b) obtained by the present invention is improved by about 1.1 dB over the conventional (a). Can be.

And as shown in Figure 5b, it can be seen that the Ec / Io signal (c) obtained by the present invention is improved by about 1dB than the conventional (d). In addition, as shown in Figure 5c, it can be seen that the T_Adjust signal f obtained by the present invention is improved by about 22dB than the conventional (e).

Although not shown in the graph, the success rate of connection of the IS-95 signal according to the present invention is improved by about 2.6% and the C / D is also improved by about 4%.

As described above, the present invention can improve the IS-95 call quality in the subway by adding the IS-95 channel to the 1X EV BTS that operates alone in the underground environment. In other words, in addition to IS-95 BTS, which is serviced mainly on the ground, in the underground service area, IS-95 and 1X EV are serviced together with BTS for 1X EV, which can stabilize the call quality of the subway and maximize base station operation management efficiency with 1X single network operation. can do.

In addition, the present invention can improve the IS-95 mother country coverage quality by the disappearance of the RVS noise layer by the subway light scattering device.

On the other hand, the present invention is not limited to the above-described embodiment, various modifications are possible by those skilled in the art within the spirit and scope of the present invention described in the claims to be described later.

Claims (3)

In the mobile communication service network providing IS-95 service in the area where the BTS for IS-95 and the BTS for 1X EV are installed, Disconnecting the hub system and the coupler for coupling the signal of the BTS for IS-95 and transmitting to the hub system, The IS-95 terminal is added to the IS-95 service channel by adding the service channel for the IS-95 to the 1X EV BTS directly through the optical dispersion device through the added channel of the 1X EV BTS. IS-95 service network in the underground environment using 1X EV, characterized in that transmitted to. The BTS of claim 1, wherein the IS-95 service channel is turned off in the BTS for IS-95 and the remaining service channel of the IS-95 is beaconed so that an optical signal transmitted to the channel is the first or the first BTS for the 1X EV. IS-95 service network in underground environment using 1X EV, characterized in that the transmission on the second channel. The IS-95 service network in an underground environment using 1X EV according to claim 1, wherein the IS-95 service channel added to the 1X EV BTS is a second channel.