Handbook

ClearFill Star CDMA
1100187 Rev. 1.0
Page 19 of 152
The simplexed twin BSI rack supports a carrier capacity of 2 CDMA carriers (realized via two
separate BSI in one housing).
 The Simplexed Twin BSI can be fed by two external power supplies (one for each
BSI).
 The external power supply port is at the rear side of the housing.
 Minimum spacing of two RF channels that are supported: 2.5MHz.
 The frequency band and channel allocation are controlled separately for each BSI
unit via NMS.
 LEDs indicate the BSI status for each BSI unit independently (locally).
2.2.2 Remote Radio Head (RRH)
The RRH converts incoming Ethernet packets into downlink RF signal to radiate it out to the
mobiles. Receiving uplink signals from the mobiles are converted into outgoing Ethernet
packets. The RRH synchronizes its frequency and timing to the BSI/BTS. The RRH is
powered over Ethernet to eliminate the requirement of an AC drop for installation, which
provides significant cost saving. To strive for low equipment cost, the RRH uses handset
technology for its RF transceiver function.
The summing function is implemented in each RRH. When activated a group of RRHs send
their packets to a designated RRH, which combines them with its own uplink data to form a
signal stream to be sent to either the BSI or another summing RRH. By locating the summing
function in the BSI and RRHs, an off-the-shelf Gigabit Ethernet switch can be used in the
ClearFill®Star network.
2.2.3 Gigabit Ethernet Switch (GES)
An Ethernet switch directs data packets to their destination by using their MAC address. In a
ClearFill®Star network, Gigabit Ethernet is used because of the required data rate and
latency. The switches need to support VLAN and priority switching. Commercial off-the-shelf
GES could theoretically be used as data transport network, but special MIB files would have
to be implemented in order to be able to connect NMS to the GES. Therefore, the
ClearFill®Star end-to-end solution offer includes a GES released to operate with BSI and
RRH. The switch can also be used to source DC power for the RRHs over the CAT5 cables
using the POE standard.
Gigabit Ethernet is required due to the link to link synchronization that is essential for the
overall system synchronization.
2.2.4 Supported Ethernet Standards
The distribution of signals between BSI-GES-RRH and GES-NMS is done via Gigabit
Ethernet Network in accordance to the protocol specified in ClearFill®Star.
The distribution of signals between GES-GES is done via Gigabit Ethernet Network in
accordance to the standards defined in Table 1.