Wirnet iBTS
Document title : Installation and
Maintenance Manual
Version : 2.0
Author : SNI
Date : 04/12/2018
Classification
This document is the strict property of Kerlink and shall not be either copied nor sent without express
written authorization of Kerlink
Internal Use
Kerlink m2m technologies reserved rights
Confidential
Kerlink – 1 rue Jacqueline Auriol – 35235 THORIGNÉ-FOUILLARD
Page 152 / 221
Strict confidential
Figure 93 : Typical gain of a sectorial antenna
Then, taking into account the performance of the antenna, we need to get about 10 to 20dB
more isolation to meet the 50dB isolation between antennas.
A gap of 1 meter between antennas would insure 30dB additional attenuation.
Therefore, our recommendation is to have the LoRa antenna just above the BTS antenna
with 1 meter gap min.
Placing the LoRa antenna below the BTS antenna could be also possible. However, this is not
recommended as reception could be impacted by metallic structures in the close area.
3.4.1
Wirnet iBTS 868
Co-localization is possible with the following BTS:
-
EGSM900, GSM1800, GSM1900
-
UMTS900, UMTS1900, UMTS2100
-
LTE800, LTE 900, LTE 1800, LTE 2100, LTE 2300, LTE2600
The most difficult use case is the LTE 800 band that is very close to the 868MHz band.
Actually, the end of the LTE 800 band is 862MHz whereas the beginning of the 868MHz band
is 863MHz. Insuring -80dBm/100KHz at 862MHz while transmitting at 863MHz or even at
868MHz is not achievable with the state of the art of SAW filters. Therefore, the Wirnet iBTS
gateway embeds specific SAW filters allowing the transmitter (LoRa-LOC module) to achieve
the -80dBm/100KHz spurious limit in the LTE 800 band.
Co-localization is not possible with GSM850, UMTS850 and LTE850
Note 1:
In India, co-localization with CDMA800 / LTE 850 requires usage of a specific cavity filter.
See §1.8.3.1. Contact KERLINK for more information.
