Service Manual

LGP-2300/2310W
LG Information & Communications, Ltd.
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conditions and message/data; both of them utilize four-stage frames of 14400,7200,3600,1800 bits per second.
In addition, this type of variable voice encoder utilizes adaptive threshold values when selecting required data
rate. It is adjusted in accordance with the size of background noise and the data rate is increased to high rate only
when the voice of caller is inputted.
Therefore, background noise is suppressed and high-quality voice transmission is possible under the
environment experiencing serious noise. In addition, in case the caller does not talk, data transmission rate is
reduced so that the transmission is carried out in low energy. This will reduce the interference on other CDMA
signals and as a result, improve system performance (capacity increased by about two times).
Also,compared to the existing CDMA cellular system’s 9600 bps vocoder rate,the PCS’ vocoder rate is up to
14400 bps, providing relatively better voice quality (almost twice better than the existing 800MHz CDMA
cellular system) almost comparable to the landline service.
2.4 Protecting Call Confidentiality
CDMA signals have the function of effectively protecting call confidentiality by spreading and interleaving call
information in broad bandwidth. This makes the unauthorized use of crosstalk, search receiver, and radio very
hard substantially. Also included is encryption function on various authentication and calls for the double
protection of call confidentiality.
2.5 Soft Handoff
During the soft hand-off, the cell site already in the busy state and the cell site to be engaged in the call later
participate in the call conversion. The call conversion is carried out through the original call connection cell site,
both cell sites, and then, new cell site. This method can minimize call disconnection and prevent the user from
detecting the hand-off.
2.6 Frequency Re-Use and Sector Segmentation
Unlike the existing analog cellular system, the CDMA system can reuse the same frequency at the adjacent cell
and accordingly, there is no need to prepare a separate frequency plan. Total interference generated on mobile
station signals received from the cell site is the sum of interference generated from other mobile stations in the
same cell site and interference generated from the mobile station of adjacent cell site. That is, each mobile
station signal generates interference in relation to the signals of all the other mobile signals.
Total interference from all the adjacent cell sites is the ratio of interference from all the cell sites versus total
interference from other mobile stations in the same cell site (about 65%). In the case of directional cell site, one
cell normally uses a 120°sector antenna in order to divide the sector into three. In this case, each antenna is
used only for 1/3 of mobile stations in the cell site and accordingly, interference is reduced by 1/3 on the average
and the capacity that can be supported by the entire system is increased by three times.