Product Description

nanoBTS Product Description Hardware Specification

3.1.6 DC Power

Power is expected by the unit on the Ethernet connector, according to IEEE802.3af option

B or A. Option A is implemented with Or-ing diodes from the unused wires, and results in

reduced supply margin and efficiency. Option B is preferred, therefore. See section 3.2.1

for more information.

The 139/140 series is designed to meet IEEE802.3af. Interoperability with 3rd party

802.3af supply equipment is not warranted. The unit is sold with its own mains power

supply (Product 109), which inserts power onto the Ethernet cable. In addition, the 165 unit

also has a separate connector for a 48V DC supply.

DC Power consumption is less than 13W.

3.1.7 TIB (Timing Interface Bus)

The TIB consists of two 10-way RJ45 connectors, a TIB-in and a TIB-out.

The TIB is required to synchronise the GSM frames between nanoBTS units acting

together as a single multi-TRX BTS. TIB-in accepts GSM-frame timing from a preceding

TRX and TIB-out generates it for the next TRX.

TIB-out

Current-mode LVDS drive, transformer coupled. Clock is

divided system clock (26MHz/16).

TIB-in

LVDS, internal termination gives typically 300mV peak-to-

peak when driven by TIB-out.

Reference Clock Input External reference clock (10MHz), with detect circuit.

Frame Sync Via removable link (for development / TA testing)

Security dongle

Support for detection of external dongle on TIB, connected

to GPIO on PPC.

Maximum TIB cable length 1.5m

Drive control

Clock output to be enabled by software. This facilitates

detecting position within a chain of BTS’s.

Serial Interface From PPC / ULM (via link on PCB).

FPGA Serial Output For development logging output (via link on PCB).

TIB Spare 1 and 2 From FPGA (via link on PCB).

Connector

10 way RJ-45 with polarisation key to prevent insertion of

standard Ethernet connector. Connectors and internal

circuitry tolerant to hot insertion, removal and reversal of TIB

in and TIB out cables.

Accessibility Accessible in-situ. No protective cover.

ESD protection

Protected to Human Body / Equipment Level discharges and

line induced surges. Protected against forced insertion of

48V Ethernet into TIB connectors, when debug links

removed.