3. Baseband Description Baseband 6630
Main Features
The main features of the baseband are the following:
• NR
• LTE (FDD and TDD), WCDMA, GSM
• Ericsson Spectrum Sharing (Baseband 6630)
• 5G Plug ins
• Massive-IoT
• NR Upper Layer vRAN
• Elastic RAN
• Mixed Mode
• Backhaul cascading
Baseband 6630 is self-maintained 19-inch unit with an easily removable fan
tray unit. each unit can be installed standalone in any 19-inch rack or cabinet
or in an RBS.
Baseband 6630 facilitate a scalable, modular system with one or more indoor
19-inch baseband units and a number of external radios. Figure shows the 19-
inch Baseband installed in a rack and connected to external radios.
4. BBU Function Description
The Baseband has the following functions:
•Timing function
•Loadable software
•Downlink (DL) baseband processing
•Uplink (UL) baseband processing
•IP traffic management
•Radio interface
•Backhaul handling
•External synchronization
GNSS Active Antenna
6. Main Features
The AIR unit is an Advanced Antenna System with
beamforming and Full Dimension Multiple Input
Multiple Output (FD-MIMO) technology, capable to
fully utilize radio resources in both azimuth and
elevation.
The main benefits compared to previous macro
solutions are the following:
•Enhanced coverage – High gain adaptive
beamforming
•Enhanced capacity – High order spatial
multiplexing and multi-user MIMO
•Advanced RAN features – Vertical/horizontal
beamforming
•Improved network performance – Low inter-cell
interference
The AIR unit is designed for outdoor
installations, intended for pole, wall, tower, or
mast mounting. It operates over LTE TDD radio
access technology.
The following are the main features of the AIR
unit:
•Two-wire (DC-C) power connection
•LTE TDD
•64 transmitter/receiver (64TX/64RX) branches
•10.3 Gbps Ethernet
Antenna Integrated Radio Unit Description AIR 6468
7. Optical Indicators
The AIR unit is equipped with optical indicators that show the
system status. The location of the optical indicators is shown in
Figure
Table below describes how to interpret the optical indicators on
the AIR unit
9. Optical Cable Interface
The optical cable interfaces provide connections to optical cables for traffic and timing signals between the AIR and a
Baseband unit. A Small Form-factor Plugable (SFP)+ is used to connect the optical cable to the AIR
Note - The AIR uses SFP+ modules for optical transmission and optical radio interfaces on the data ports
eCPRI Interface - The AIR unit sets up connection with Baseband via eCPRI interface, a 10.3 Gbps Ethernet port
Sync Interface
This interface is reserved for future use as a 1.25 Gbps Ethernet port connected to TCU, to receive sync timing
from TCU through PTP protocol. The interface is hardware prepared as a 10.3 Gbps eCPRI interface. The connector
is SFP+
External Alarm/EC Light Interface
The EC light port will deliver communication signals and alarms between the optional PSU and the AIR
The alarm port supports two external alarms
The external alarm cables are implemented only for AIR 6468 B41E
Optical Indicators
Optical indicators show the system status
TX Monitor Interface
The TX monitor interface provides monitoring of output power and performance
10. SYSTEM MODULE USED IN MUMBAI CIRCLE:
System Module Type
ASIA AirScale Common
Flexi System Module Outdoor FSMF
11. Flexi System Module Outdoor FSMF ASIA AirScale Common
FSMF
FBBA
FBBC
Airscale AMOB
ASIA
ABIA
15. AirScale Capacity ABIA plug in unit
Customer Confidential
RF1 RF2 RF3 RF4 RF5 RF6
Capacity plug in unit:
• Cell specific baseband processing
• Up to 6 PIU in Subrack for flexible expansion of BTS baseband capacity
• RF Module connectivity
• 6 x OBSAI/CPRI up to 9.8 Gbps
16. RF Module Type Band Technology Output power Number of Antenna Ports Number of TXRX
AHEC 1800 MHz FDD-LTE 2x80 W 4 (TX/RX - RX - TX/RX - RX) 2TX4RX
AREA 1800 MHz FDD-LTE 6x80 W 6 (TX/RX - TX/RX - TX/RX - TX/RX - TX/RX - TX/RX) 6TX6RX
FXEB 1800 MHz FDD-LTE 3x80 W 6 (TX/RX - RX - TX/RX - RX - TX/RX - RX) 3TX6RX
FXED 1800 MHz FDD-LTE 6x60 W 6 (TX/RX - TX/RX - TX/RX - TX/RX - TX/RX - TX/RX) 6TX6RX
FXEF 1800 MHz FDD-LTE 3x80 W 6 (TX/RX - RX - TX/RX - RX - TX/RX - RX) 3TX6RX
FRGP 2100 MHz FDD-LTE 3x60 W 6 (TX/RX - RX - TX/RX - RX - TX/RX - RX) 3TX6RX
FRGQ 2100 MHz FDD-LTE 2x40 W 2 (TX/RX - TX/RX) 2TX2RX
FRGT 2100 MHz FDD-LTE 3x80 W 6 (TX/RX - RX - TX/RX - RX - TX/RX - RX) 3TX6RX
FRGY 2100 MHz FDD-LTE 2x60 W 2 (TX/RX - TX/RX) 2TX2RX
AANB 2300 MHz TD-LTE 120 W total (3x40 W or 2x60 W) NA 64TX64RX
AZNA 2300 MHz TD-LTE 4x40 W 4 (TX/RX - TX/RX - TX/RX - TX/RX) 4TX4RX
FZNC 2300 MHz TD-LTE 6x10 W 6 (TX/RX - TX/RX - TX/RX - TX/RX - TX/RX - TX/RX) 6TX6RX
FZNI 2300 MHz TD-LTE 4x30 W 4 (TX/RX - TX/RX - TX/RX - TX/RX) 4TX4RX
FHDI 900 MHz FDD-LTE 2x60 W 2 (TX/RX - TX/RX) 2TX2RX
FXDJ 900 MHz FDD-LTE 3x60 W 6 (TX/RX - TX/RX - TX/RX - TX/RX - TX/RX - TX/RX) 6TX6RX
FXJB 900 MHz FDD-LTE 3x80 W 6 (TX/RX - RX - TX/RX - RX - TX/RX - RX) 3TX6RX
RF MODULE USED IN MUMBAI CIRCLE:
22. Flexi Fiber Optical Distribution Unit (FODA) is a
stand-alone outdoor product which can be used for
cable routing between the RF Module and System
Module. Together with the combination of jumper
cables and different length of feeder cables, it
simplifies site installation. The FODA provides up to
12 outputs for RF Modules or RRHs. The FODA
supports different installation options with
mounting brackets. It can be assembled to a 3U
casing together with the 2U PDU. It can also be
mounted directly on a pole/mast or wall.
Flexi Fiber Optical Distribution Unit
(FODA) operation:
RF Chaining in SRAN
• FXEB To FXEB & FHDI To FHDI RF chaining at SRAN Site can be done due to Free Port
unavailability in FODA
• FODA card has 12 Ports available – 6 TDD, 1 3G, 1 L900, 2 FDD/2G, 2 Twin Beam or additional
sector
• To add new RF Module, we need additional FODA which is not being ordered due to OPEX
planning
• Hence, RF Chaining Feature (RAN1881/LTE977: RF Chaining) is being used at sites
23. • It is allowed to chain any two RF cell sets with
OBSAI optical links or up to four RF cell sets with
Nokia CPRI links if it is technically feasible.
Possibility of combining the supported SBTS cell
sets depends only on the HW limitations of the
radio modules used in configurations, the
number of optical ports in the radio modules and
the number and capacity of OBSAI or Nokia CPRI
optical links (links between SM and 1st radio and
links between radio modules).
• If OBSAI cable goes faulty or any Fault
Maintenance activity is being done on Master RF
Module so that it takes restart, we will observe
outage on both cells connected to master and
slave RF Modules due to RF chaining being used.
RF Chaining in SRAN
24. Above Fig. is the common Airscale site connectivity with following Cells configuration:
TDD20 & TDD10 – 3 Cells (4x4 MIMO) + 1 Twin Beam Cell (4x4 MIMO) – 2X6GBPs SFP and CPRI are connected to
each RFM
FDD – 3 Cells (2X2 MIMO)
L900 – 3 Cells
WCDMA – 3 Cells
All the 12 ports of FODA is occupied and there is no port left for new CPRI cable connectivity incase L2100 is
integrated or new TDD/FDD/L900 Cell is integrated
L2100 – Need additional CPRI connectivity between existing WCDMA RFM and ABIA
New Cells – Need CPRI connectivity between new RFM and ABIA
Common Airscale Site Connectivity
Diagram:
RF Chaining in SRAN
25. RF Chaining is illustrated in above Fig. (Black Lines)
1. CPRI for 2nd FDD1800 RFM has been removed from FODA and RFM is chained through 1st RFM
2. Additional CPRI is connected to Freed input port of FODA from L2100 configured ABIA card
3. Freed Output Port of FODA is now used to Connect additional CPRI to L2100 RFM
4. Same Free Port of FODA can be used for additional FDD/L900 Cell to be integrated instead of L2100
5. All 3 Sectors of FDD1800 will work 2X2 MIMO with RF Chaining
6. If 1st RFM goes Faulty, all 3 sectors will go down due to RF chaining
7. Without RF Chaining, Cell operation degrades but Cell doesn’t go faulty
Airscale Site Connectivity Diagram with RF Chaining:
RF Chaining in SRAN
26. Instead of using 2X6GBPs SFP for TDD RFM connectivity, we can use 1X10GBPs SFP thereby reducing the number of CPRI
cables in TDD
4 Ports can be Freed by using 10GBPS SFP in TDD which can be utilized for New cell addition or L2100 integration
As shown in above figure, Additional CPRI for L2100 or New Cell is connected to Free Port of FODA
Solution to overcome RF Chaining:
RF Chaining in SRAN
27. GPS ANTENNA & CABLE ISSUE
Hard Ware Type- GPS Antenna & cable
Issue- GPS Antenna & cable fault rate is high
Impact- High CMO
*Few possible reasons behind high Failure of GPS
Antenna & Cable –
GPS Antenna & cable pin getting damage due to
corrosion as moisture found inside connector
GPS Cable found damage at multiple places due
to RAT/Squirrel issue as it’s not a armored cable.
GPS cable quality is not good.
Recommendation-
This issue can be resolved by using Good quality of
GPS Antenna & Armored GPS cable
No provision for weather proofing,
moisture found in connector
Cable getting damaged as it is non-
armored cable
28. The synchronization proceeds according to the following steps:
1. The System Module receives pps from the GPS/GNSS through
Sync In
2. The System Module generates a System Clock and a System
Synchronization Burst
3. The periodic Synchronization Burst, which contains air-
interface-specific frame numbers and time references, provides
time synchronization between BTSs to reduce interference
4. The System Module forwards the System Clock and a System
Synchronization Burst to the RF Module(s) through an optical
interface
5. The DC power feed (12 V DC) for the receiver is supplied
through combined power/data cables that are listed at the start
of this chapter.
GPS Antenna
Mounted on Pole
GPS Cable routed
through pole and
connected to
SYNC IN port of
System Module
System Module FSMF/ASIA
Damage/Corrosion
points are encircled
in RED
GPSANTENNA&CABLEISSUE
GPS Antenna’s & GPS Cables faults were increased in monsoon. Outage instances only observed bcoz of GPS Antenna/Cable faulty)
During our analysis done for high failure rate we found corrosion inside GPS connector & cables found damaged
Sites visited jointly after escalating the high failure rate of product & increase in Active Outages by Nokia SISO Team/Ericsson/Bharti
where same scenario was proven
It seems Product issue of GPS Antenna and sub-standard quality of GPS cable. Observations have been shared to Bharti Circle Team.
30. L-TYPE JUMPER ISSUE
Hard Ware Type- L-Type Jumper
Issue- Facing major fault in LTE jumper installed at TDD-LTE sites. As per our
observation found major cause of fault is improper make of Jumpers. Sites
having L-Type connector at RF module end (FZNI) are having more count of
VSWR Alarms & contributing in Outages too.
Impact- Whenever heavy wind/rain occurs, the count of TDD VSWR Alarms
increased drastically & closed after Jumper replacement, impacting QIA
count, CMO, RF KPI’s & Customer Complaints
*Few possible reasons behind high Failure of these Jumpers* –
Sealing & Taping not properly done bcoz of Right angle & chances of
water insertion are always high.
Not able to attach with tie nearer to RF module & chances of failure
increases due to juggling during wind & rain.
The traction is more towards ground wrt straight connectors & the
welding joint may disconnect/damaged quicker.
Quality of Jumper in any particular lot as procured from local vendor
(Amphenol).
Recommendation- Replacement of L-Type Jumper with I-Type Jumper.
31. System
Module
FSMF/ASIA
FZNI RF module mounted on Pole
03 FZNI RF Modules installed/site
Jumper connectivity between RF Module and Antenna – Ideally
it should be I-Type (as shown in fig above). But, in Mumbai, L-
Type Jumpers are used (as shown in fig below)
Damaged points are encircled in
RED
L-TypeJumperIssue:CurrentScenario-Mumbai
