IN865-867 & Antenna tuning

Gateways MultiTech Gateways
1

We have been using URSALINK LORAWAN gateway for a while.
If we use EU 868MHz antenna, when our end nodes are using IN865-867 tuned antenna.
We are using TTI as our network server, and we observed that even though the end nodes are very close (around 10ft) to the gateway. Still SF12 is being used, not sure why.

Some of the questions in our mind, for which we are seeking help from the community to answer them:

  1. Using 868MHz antenna on gateway and IN865-867 tuned external antennas at end nodes, will this factor increase data loss.
  2. Using 868MHz antenna on gateway and using IN865-867 tuned internal antenna at end nodes, will this factor increase data loss.
  3. Why SF12 is being used. Who makes the choice of SF. TTI network server or gateway. Can someone clarify
2

It wont make a lot of difference if you use an antenna tuned (whartever that means) for 865-867Mhz on 868Mhz, the tuning is not that sharp, unless these are high gain highly directional antennas, which is not the type of antenna used on TTN.

4

The first choice is made by the node. (When ADR is enabled, the network server might tell the node to change its settings after some time. In TTN, the gateway only forwards traffic, nothing else.)