Wirnet™ iFemtoCell hardware architecture

The Wirnet iFemtoCell is an Indoor LoRaWAN nano gateway for Internet of Things networks.

The Wirnet iFemtoCell hardware characteristics are:

• Low power supply consumption.
• Easy installation.
• Small casing.
• LoRaWAN™ communication.
• Bidirectional.
• Robustness to interferences.

Wirnet iFemtoCell is a nano gateway mainly designed for indoor applications to ease:

• The deployment of IoT solutions easier by enabling network densification in buildings.
• underground locations (in addition to outdoor solutions like Kerlink Wirnet Station or Kerlink Wirnet iBTS).

Wirnet iFemtoCell is typically dedicated to:

• Smart Building & Facilities.
• Smart Industry.
• Smart Cities applications.

With Wirnet iFemtoCell, the operator is able to choose the backhaul network between Ethernet or LTE/HSPA/GPRS or Wi-Fi.
The Wirnet iFemtoCell gateway includes an omnidirectional 3dBi internal Wi-Fi antenna.

The following block diagram details the architecture of the radio front-end:

The radio front-end is derived in three different versions to cover the unlicensed bands:

• 868MHz (863-873MHz)
• 915MHz (902-928MHz)
• 923MHz (915-928MHz)

The frequency bands covered by the Wirnet iFemtoCell depends on the version used (868, 915 or 923).

The LoRa modem (SX1301) can handle up to 10 simultaneous channels (including 8 multi-SF) and a single antenna port.

• The baseband chip is from Semtech.
• 8 multi-SF channels are 125kHz/5kbps max, using the LoRa modulation
• 1 channel is SF7/250kHz, using the LoRa modulation
• 1 channel is 250kHz | 500kHz /50kbps max, using the FSK modulation (good radio conditions)

There are two SX1257 transceivers capable of 0.8MHz bandwidth each.
Frequency planning must be set accordingly (e.g. place channels in two groups of 0.8MHz span each).