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Multi Radio Basic
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Slide 1For internal use
Flexi Multiradio BTS
For internal use
Flexi Multiradio BTS
Contents
For internal use
For internal use
Flexi Multiradio BTS
Introduction
Flexi Platform is a gateway to the future BTS development
process
Common HW platform for different access technologies: GSM/EDGE,
WCDMA, LTE
High flexibility supporting various BTS configurations
Flexible HW architecture allowing easy development towards the
multiradio HW platform
BTS development path
For internal use
Flexi Multiradio BTS
Introduction
The existing Flexi EDGE BTS is the baseline for Multiradio BTS
solution:
Revolutionary approach to base station design
BTS built with self standing modules
BTS cabinet now just one of the installation options
New possibilities in site selection and build-out
Flexi EDGE BTS main elements
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
Flexi Multiradio BTS
Introduction
The existing Flexi EDGE BTS is the baseline for Multiradio BTS
solution:
All-purpose base station
Macro & micro coverage
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
One all-purpose Base Station
For internal use
For internal use
Flexi Multiradio BTS is a common HW platform to be used for
different access technologies: GSM/EDGE, WCDMA, LTE
Radio access functionality is shifted from dedicated HW to
dedicated SW
Radio Modules (RFM/RRH) can transmit and receive multicarrier
signals of multiple radio technologies concurrently
Each RM’s branch (pipe) can support several carriers (frequency
blocks for WCDMA/LTE and virtual TRXs in case of GSM/EDGE) within
the available RM’s bandwidth or the bandwidth can be shared between
different technologies
Different technologies share the same RF Power amplifiers within
one band
The output power of the RF power amplifiers is split between the
RATs
Example: EDGE and WCDMA carriers in Concurrent Mode
Basic MR configuration: 3 HW units
Flexi Multiradio BTS
Flexi Multiradio BTS
For internal use
Up to 18 GSM TRX; 3 sector support; 3x 60W@antennaconnector
Flexible capacity increase from small to very large
configurations
Up to 12 cells with 1-12 TRX/cell; Up to 36 TRX per BTS (BCF)
Up to 108TRX (36+36+36) in one sits using Multi BCF/common
BCCH
Very High capacity sites possible without any cabinets
Antenna Optimized Configurations
Min GSM configuration
6/6/6, 2 modules
36/36/36, 9 modules
Max GSM configuration/BCF
For internal use
Existing Ultrasite BTS
RG10 ED** (Q2 2009)
Basic/Existing BR features
**RG10ED will have BTSPlus support@flexi BSC. Co siting comes in RG
20
ESMB
For internal use
Flexi Multiradio BTS
BTS functionality for GSM/EGPRS
NodeB functionality for WCDMA
eNB functionality for LTE
System Module GSM/EGPRS
GSM/EGPRS
WCDMA
LTE
can be combined in a flexible way to configure a BTS for GSM/EGPRS,
a NodeB for WCDMA, a eNB for LTE or a combination.
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
Flexi Multiradio BTS
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
Flexi Multiradio BTS
The installation options are compatible with the Flexi BTS
Complies with Flexi powering principles and compatible with Flexi
power modules and
Compatible with Flexi antenna line
Flexi EDGE transmission plug in units can be used within Flexi
Multiradio GSM/EDGE system module (ESMB/C).
Can be synchronized with the existing Flexi system modules.
Compatible with Flexi alarm extension module (FSEB)
The Flexi Multiradio RF Modules are not compatible with existing
Flexi EDGE system module (ESMA)
The Flexi Multiradio GSM/EDGE system module (ESMB/C) is not
compatible with Flexi EDGE DTRXs (EXxA) or RTCs (ECxA)
Compatibility
For internal use
For internal use
Flexi Multiradio BTS GSM/EDGE Architecture
Main functions of the modules
The System Module is the center of the system. It has all the
external interfaces of the BTS (apart from the antenna interfaces).
Main functions of the System Module are the Transport, BTS O&M,
synchronization, power distribution and baseband processing
functions. System Module interfaces support up to four Radio
Modules with local power feed. Radio modules are connected to
System Module through RP3-01 interfaces.
The Radio modules and RRH’s contain both RF BB and RF functions.
They are multistandard and multicarrier transceivers. RF BB
includes RP3-01 interface with multifunctional ASICs and
controller. In addition of TX/RX lineups module has integrated
front end. RFM front end will be implemented with SW tunable
filters. RRH will have fixed full band filters.
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
There are 2 variants of GSM/EDGE System Module: ESMB &
ESMC
Note: Flexi EDGE BTS specific system module ESMA is not supported
in Flexi Multiradio BTS
Main functions of the System Module:
GSM/EDGE BTS O&M
GSM/EDGE Configuration Management
Abis and transport
Power distribution
GSM/EDGE baseband
BTS synchronization
Flexi Multiradio BTS
RP3-01 (OBSAI) interfaces and related multiplexing functions
ESMB / ESMC
For internal use
Flexi Multiradio BTS
General Information
ESMB/ESMC has all the GSM/EDGE specific external and internal BTS
interfaces (except the antenna interfaces)
48 VDC distribution, 4 radio outputs + 1 AUX output
Abis Interface,
External Alarm & Control Interface 12 inputs, 6 outputs and
optional 12 input extension
4 pcs OBSAI RP3-1 Interfaces
BTS Reference Clock / Synchronization between BTSs
GSM frame clock input and output
GSM frame number input and output
2MHz synchronization input and output
1PPS input
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
ESMB for smaller configurations up to 18 TRX
ESMC for bigger configurations up to 36 TRX
IP 65 protected
Temp range -35 to +55 degrees C
System Module is the centre of the system. Main Functions
include:
BTS Operations and Maintenance
Optical OBSAI connectivity and related multiplexing/chaining
functions
Power distribution to the RF modules
High capacity GSM baseband functionality for up to 18/36 TRX
BTS Synchronization
For internal use
Flexi Multiradio RF Module A (FXxA) - RFM
FXxA RFM variants (HW Rel 2.2) are WCDMA & LTE & GSM
capable
RFM is optimized for 3 sector Macro BTS use (the module consists of
3 independent branches (pipes))
Each branch (pipe) can transmit and receive multicarrier signals of
multiple radio technologies concurrently
Flexi Multiradio BTS
Sector1 1÷6 carriers
Sector2 1÷6 carriers
Sector3 1÷6 carriers
DC Power supply input
For internal use
The transmitter and receiver chains and the front end
Software tunable filters
Integrated antenna line supervision and MHA support
OBSAI connectivity (optical 3 x RP3-1 interfaces)
RFM is a single band module
There are different RFM variants (FXxA) available to support
different frequency band
MCPA – Multi Carrier Power Amplifier
LNA – Low Noise Amplifier
For internal use
Flexi Multiradio BTS
General Information
RFM is a single band module. Separate FXxA modules for each
frequency band are supported by Flexi Multiradio BTS
RF Module is able to work within the whole 3GPP band, however, its
operational bandwidth in UL and DL is limited
The RF bandwidth is determined by two "blocks" in the RFM
module:
SW Tuneable (STuFF) Front End Filter and
Digital PreDistortion (DAPD), which is used to improve the TX
performance in the Multiradio capable BTS
The carriers supported by the pipe must stay within that RFM
sub-band, however, sub-band window can be tuned to cover the
desired frequencies from the 3GPP band
STuF and DAPD are automatically tuned by BTS SW, based on allocated
carriers on each pipe
Flexi Multiradio RF Module A (FXxA) - RFM
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
Each RFM branch (pipe) can support several carriers (frequency
blocks for WCDMA/LTE and virtual TRXs in case of GSM/EDGE) within
the available RFM bandwidth or the bandwidth can be shared between
different technologies
Note: The power amplifier (MCPA) amplifies simultaneously all the
carriers defined within its bandwidth No antenna combiners are
needed to combine the carriers to a common antenna line (therefore
combining losses don’t need to be considered in the Link Budget
calculations)
Flexi Multiradio BTS
f1
5Mhz
f2
5Mhz
f3
5MHZ
f4
5Mhz
f1
f2
f3
f4
f6
f5
F1
X=1.4/3/5/10/15/20MHz
f2
f1
5Mhz
F
5Mhz
f1
f3
F1
f4
For internal use
Flexi Multiradio BTS
General Information
Up to 6 carriers per RFM pipe can be defined for GSM/EDGE
Single RFM capacity is up to 18 carriers (TRXs), 6+6+6 TRXs
Carriers can be defined using 100 kHz frequency raster (minimum 400
kHz of the carrier separation in the pipe needs to be kept between
GSM/EDGE carriers
Flexi Multiradio RF Module A (FXxA) - RFM
Frequency, RFM variant
60W
60W
60W
60W
MCPA Concurrent mode(s): Max supported by HW: supported by HW:
GSM/LTE GSM/WCDMA GSM/WCDMA/LTE WCDMA/LTE
5G+1U/1L(5MHz) 2G+2U/1L(10MHz) 1U+1L(10MHz)
5G+1U/1L(5MHz) 2G+3U 4G+2U/1L(10MHz) 2G+1U+1L(10MHz)
2U+1L(10MHz)
5G+1U/1L(5MHz) 2G+3U 4G+2U/1L(10MHz) 2G+1U+1L(10MHz)
2U+1L(10MHz)
5G+1U/1L(5MHz) 2G+3U 4G+2U/1L(10MHz) 2G+1U+1L(10MHz)
2U+1L(10MHz)
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
Flexi Multiradio BTS
Flexi Multiradio Remote Radio Head (FHxA) - RRH
RRH is optimized to support single sector with 2 RX and 2 TX
diversity (2x2 MIMO)
RRH consists of two individual radio branches (pipes) designed to
transmit and receive multicarrier signals of multiple radio
technologies
Each pipe supports 1 x TX and 1 x RX chain
RRH is equipped with:
2 RP3 01 OBSAI Interfaces, for System Module connectivity and RRH
Chaining
2 TX/RX Antenna Interfaces
Integrated Duplex Filters
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
Flexi Multiradio BTS
Flexi Multiradio Remote Radio Head (FHxA) – RRH
Single RRH capacity is up to 12 carriers (TRXs), 40+40W (6+6
TRXs)
New Flexi Multiradio Modules
(**) - The capacities shown here are per MCPA or per branch. RRH
has 2 MCPA branches. So the total RRH HW capacity is twice the MCPA
Concurrent Mode as shown here
Frequency, RRH variant
1.4/3/5/10/15/20 MIMO
1.4/3/5/10/15/20 MIMO
2 RAT mode for RRH unit (Dedicated or Concurrent mode for
MCPA)
GSM and/or WCDMA and/or LTE
GSM and/or WCDMA and/or LTE
Output power
MCPA Concurrent mode(s)** Max supported by HW: GSM/LTE, GSM/WCDMA
GSM/WCDMA/LTE WCDMA/LTE
5G+1U/1L(5MHz) 2G+3U 4G+2U/1L(10MHz) 2G+1U+1L(10MHz)
2U+1L(10MHz)
5G+1U/1L(5MHz) 2G+3U 4G+2U/1L(10MHz) 2G+1U+1L(10MHz)
2U+1L(10MHz)
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
Flexi Multiradio BTS
There are different working modes of Flexi Multiradio BTS
Dedicated Mode each technology has its own Radio Resources
connected to the System Module
Concurrent Mode Radio Resources (e.g. RFM) are shared between
technologies (different RAT in the same frequency band)
Dedicated RFM each Flexi System Module has its own RFM
connected
RFM is shared each Flexi System Module has its own RP3-1
connections to shared RFM
1
2
For internal use
Flexi Multiradio BTS
RF configurations
Dedicated SW features need to be used to enable RFM sharing between
different technologies
RG10EP5.1 / RU20EP1(complete support in RU30) : RF sharing WCDMA –
GSM (RAN1770)
RG25 / RL20: RF sharing 2G – LTE (BSS21520 & LTE447)
RU30 / RL30: RF sharing WCDMA – LTE (RAN2126 & LTE435)
Allowed combinations of multi-technology carriers and the number of
supported shared / dedicated Radio Modules is strictly defined by
the features
Concurrent Mode
Flexi Multimode System Module FSMD/FSME (HW Rel 2) needs to be used
for WCDMA/LTE to support Radio Resource sharing in the concurrent
mode
ESMB/ESMC System Module is required to support GSM/EDGE
PWR
PWR
PWR
PWR
3 HU
Transmission sub-module
3x 100 & 1000 BaseT Ethernet
External synchronization input and output
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
Flexi Multiradio BTS
RF configurations
Flexi MR BTS is seen as two separate logical network elements with
common Radio Resources
Concurrent Mode
RFM and antenna lines are shared
In the concurrent mode both system modules must be synchronized
together
Each module has its own power supply
Both system modules can feed the power to the RFM
Each radio technology has dedicated logical backhaul connections
(Abis, Iub and S) to radio controllers and servers (from each
logical network element)
*) on top feature
For internal use
Flexi Multiradio BTS
Several modules can be connected to ESMB/ESMC in order to:
Increase capacity above 6+6+6 TRXs
Maximize coverage (increase output power per carrier through
spreading them over more than one RFM pipe) or support coverage
boosters
Support operator's bandwidth in case it exceeds RFM’s
bandwidth
Maximum 4 RFMs can be connected
Amount of RP3-1 interfaces available in the system module limits
the number of connected RFMs
Basic 3-sectorized configuration
*) on top feature
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
Flexi Multiradio BTS
Baseband processing capacity centralized in ESMB/ESMC
supports:
Up to 6 cells (up to 12 cells in MOBSS case)
Up to 16 carriers per sector
Up to 36 carriers (12+12+12) per BTS (1 BCF)
ESMB - up to 18 carriers (TRXs) capacity
ESMC - up to 36 carriers (TRXs) capacity
Capacity above 6+6+6 can be achieved by installing additional RFM
modules per BTS configuration
More than one RFM branch (pipe) can be used in a cell
RFM branches (pipes) used in the same cell can be from the same or
different RF module(s)
GSM/EDGE dedicated mode
3-sectorized BTS site
Up to 12+12+12 (one sector shown)
2RX div applied with shared diversity paths between the branches
(both RMs tuned to the same sub-band)
Slide 40; Excel database; BTS conf.: 7÷9, 28÷31
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
Flexi Multiradio BTS
Higher capacity can be supported by the multi ESMB/ESMC
configuration
Up to 108 TRXs (36+36+36)
Multi BCF/common BCCH feature is mandatory
Max configuration (one sector shown):
Up to 36+36+36
6 RFM, 3 ESMC, MultiBCF
3 Xpol / sector
9 Xpol / site
RFMs simultaneously connected to ESMB/ESMC can be of different
frequency band, e.g.:
900 MHz 6+6+6 & 1800 MHz 6+6+6 or
900 MHz 12+12+12
1800 MHz 12+12+12
GSM/EDGE dedicated mode
*) on top feature
For internal use
Flexi Multiradio BTS
Maximize coverage (increase output power per carrier) or support
coverage boosters
TX transmit power is shared between carriers
More carriers configured per RFM branch (pipe) means lower output
power per carrier
Several RFM branches (pipes) can be used per sector to distribute
carriers and increase output power per carrier
Support operator's bandwidth in case it exceeds RFM’s
bandwidth
More than one RFM per sector might be required when the Operator’s
bandwidth (defined ARFCNs) exceeds one RFM RF branch
bandwidth
Note: It should be always verified whether the gain coming from
higher output power is not consumed by increased BTS costs (RFM
costs are a significant part of the total BTS cost)
GSM/EDGE dedicated mode
Up to 12+12+12
2RX div RFMs tuned to different frequency sub-bands (one sector
shown)
Slide 40; Excel database; BTS conf.: 19÷21, 34 ÷ 36
Maximized output power (one sector shown):
Up to 12+12+12 (2RX div shared between branches)
4 TRXs * 60W
8 TRXs * 30W
12 TRXs * 20W
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
Flexi Multiradio BTS
RF configurations
More than one RFM pipe per sector might require several antennas
installed on site
Multi Radio Combiner (MRC) can be used to combine pipes to single
antenna line
GSM/EDGE dedicated mode
Up to 12+12+12
Each pipe has its own antenna connected
Note: MRC introduces additional losses in DL & UL
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
Flexi Multiradio BTS
RF configurations
The main criteria to be considered when deciding on the
configuration are:
No of carriers per sector
No of carriers determines the minimum number of RFM modules per BTS
site and whether ESMB or ESMC has to be used
No of RFM branches (pipes) per sector
No of RFM branches determines the maximum output power per
carrier
Carriers can be spread over several RFM modules less carriers per
single RFM means higher output power
More than one RFM per sector might be required when the Operator’s
bandwidth (defined ARFCNs) exceeds one RFM RF branch
bandwidth
Coverage booster
GSM/EDGE dedicated mode
For internal use
Flexi Multiradio BTS
RF configurations
For the sake of simplicity the Typical BTS configuration list is
limited to the configurations satisfying the following
assumptions:
3-sectorized BTS site considered only
Symmetrical BTS configurations considered only (e.g. 1+1+1, 2+2+2,
etc.)
Symmetrical antenna configurations within one sector and site
2 Xpol antennas and 12 carriers per sector are the maximum
All the configurations grouped as follows:
Standard configuration (Slide 41; Excel database; BTS conf.:
1÷27)
Minimum no of RFM modules used at a cost of reduced output power
per carrier
Maximized output power (Slide 41; Excel database; BTS conf.:
28÷39)
Carriers span over several RFM modules
Maximized output power at a cost of higher number of RFM modules
used
GSM/EDGE dedicated mode
For internal use
Flexi Multiradio BTS
Resource allocation algorithm
Power Budget: Maximum total TX output power on one pipe is 60 W
which can be shared between the TRX objects allocated on that
pipe:
1 TRX = 60 W per TRX
1..2 TRXs = 30 W per TRX
….
1..6 TRXs = 10 W per TRX
Frequency Budget: All BTS TX (DL) frequencies allocated on one pipe
must be within 20 MHz window:
Example: 3 TRXs per BTS:
TRX-1 @ ARFN 1 = 935.2 MHz (BTS TX frequency)
TRX-2 @ ARFN 50 = 945.0 MHz
TRX-3 @ AFRN 100 = 955.0 MHz
All channels within 20 MHz = OK!
Extended Uplink on 1800 MHz: If two pipes are used for the same
local sector, then BTS RX (UL) frequencies on that sector can be up
to 30 MHz
If either Power or Frequency budget is exceeded, alarm is
raised:
7606 – TRX FAULTY – “TRX object allocation failed in RF
Module”
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
For internal use
Flexi Multiradio BTS
Flexi MR BTS - TX output power
The nominal output power at the antenna connector is equal
to:
60 W for the 3-sector RFM (60W per branch (pipe))
40 W for single sector RRH (40W per branch (pipe))
The nominal output power at each branch (pipe) is the maximum
cumulated sum of output powers of all the carriers (TRXs) within
that branch
The output power per carrier of a radio branch decreases with the
increasing number of carriers in the radio branch
In the concurrent mode the total output power of RFM/RRH is shared
between radio technologies:
GSM / LTE 40W / 20W or GSM / LTE 20W / 40W
GSM / WCDMA 40W / 20W or GSM / WCDMA 20W / 40W
Then the output power dedicated to each technology is distributed
among defined carriers (GSM) or limited according to installed
license (WCDMA/LTE)
Maximum output power per carrier is finally determined by the
number of defined carriers
Receive sensitivity to be the same as with existing Flexi EDGE
BTS
* © Nokia Siemens Networks Presentation / Author / Date
Company Confidential
Sensitivity at the antenna port of the BTS without MHA
GSM900
Nominal Sensitivity 2-way diversity (STIRC) dBm
Static
TU50
TU50iFH
RA250
HT100
Static
TU50
TU50iFH
RA250
HT100
TCH/FS
-112,6
-110,6
-111,3
-111,1
-111,0
-115,6
-115,7
-116,1
-116,1
-115,7
CS-1
-116,1
-110,6
-111,8
-112,0
-110,5
-119,0
-115,7
-116,4
-116,8
-115,5
CS-2
-114,0
-107,8
-108,5
-108,3
-106,9
-116,9
-113,3
-113,9
-114,3
-112,8
CS-3
-112,8
-106,1
-106,5
-105,9
-104,5
-115,8
-111,9
-112,1
-112,6
-111,0
CS-4
-107,8
-98,2
-97,9
-111,0
-105,5
-105,1
Company Confidential
Sensitivity at the antenna port of the BTS without MHA
GSM1800
Nominal Sensitivity 2-way diversity (STIRC) dBm
Static
TU50
TU50iFH
RA130
HT100
Static
TU50
TU50iFH
RA130
HT100
TCH/FS
-112,6
-110,6
-111,2
-111,2
-111,0
-115,6
-115,8
-116,0
-116,2
-115,8
CS-1
-116,1
-111,3
-111,6
-112,2
-110,2
-119,0
-116,3
-116,5
-116,8
-115,4
CS-2
-114,0
-108,3
-108,4
-108,5
-106,4
-116,9
-113,8
-114,0
-114,3
-112,7
CS-3
-112,8
-106,3
-106,5
-106,1
-103,8
-115,8
-112,4
-112,2
-112,6
-110,9
CS-4
-107,8
-96,8
-96,7
-111,0
-105,3
-105,2
For internal use
RFM has embedded Bias-T units with over-current and under-current
alarm
RFM feeds power to MHA through an antenna feeder cable
Nominal (12 dB LNA) and NSN high gain (32/33 dB and 24 dB LNA)
amplifiers are supported
2-way receiver diversity
RFM module is optimized for 2RX UL diversity (two RX paths: main
and div embedded in the module), however no diversity is supported
either
4-way receiver diversity
2 RFM branches (pipes) have to be used in parallel to support 4RX
diversity (the pipes can be connected to the same or different RFM
modules)
4RX UL diversity can only be used with Intelligent Downlink
Diversity (IDD)
Similar diversity gains as in case of the Flexi EDGE BTS can be
expected
Flexi Multiradio BTS
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
Increased output power per carrier (TRX) through carrier spreading
over more than one RFM/RRH pipe
Support for Intelligent Downlink Diversity (IDD)
Flexi Multiradio BTS
IDD can be used with 4RX or 2RX UL diversity
IDD and standard TRXs can be used in the same sector
2 RFM branches (pipes) have to be used in parallel to support IDD
(the pipes can be connected to the same or different RFM
modules)
Similar diversity gains as in case of the Flexi EDGE BTS can be
expected
Slide 41; Excel database; BTS conf.: 22÷27
Slide 41; Excel database; BTS conf.: 10÷15
RFM IDD with 4-UL Div
1 Carrier (one sector shown)
RFM IDD with 2-UL Div
1 Carrier (one sector shown)
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
Flexi Multiradio BTS makes constructing of a feederless BTS site
easier
Due to high capacity of a single RFM module the number of HW units
installed at a mast top can be reduced simple construction and easy
installation
There is a built-in (OBSAI RP3-1) interface between HW
modules
No need to insert additional optical converters as in case of the
FlexiEDGE BTS
Connection can be ensured through a multimode fibre line on the
distance up to 200 m
Power supply (48VDC) has to be provided to the RFM module by a
separate power distribution cable (up to 100m long)
FlexiEDGE BTS
Flexi Multiradio BTS
For internal use
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
Multi Carrier Power Amplifier in Flexi Multiradio BTS
Each pipe in the RF module is equipped with Multi Carrier Power
Amplifier (MCPA) that amplifies simultaneously all the GSM/EDGE
carriers defined in that cell
Up to six GSM/EDGE carriers can be defined in one pipe
In static Allocation, MCPA’s total output power is shared between
all carriers defined in that pipe
Max o/p per carrier is directly determined by the number of defined
carriers in the pipe
Max o/p per TRX = 60 W / No of carriers defined in the MCPA
More than one pipe per sector is needed for High capacity and high
coverage sites,
10W
666
12W
555
15W
444
20W
333
30W
222
60W
111
For internal use
Dynamic Power Sharing in Flexi Multiradio BTS (1/3)
Dynamic Power Sharing enables unused power from different TRXs to
be used dynamically between other TRXs of the same cell
BCCH carrier has statically allocated power
MaxBCCH o/p ≥ 60 W / No of carriers defined in the MCPA
Remaining MCPA power is dynamically allocated for TCH
carriers
MaxTCH o/p = MaxBCCH o/p
Max o/p per carrier decreases with increasing no of defined
carriers Cell coverage is reduced
Cell range
4 carriers / MCPA
6 carriers / MCPA
Max o/p per carrier does not need to be reduced with increasing no
of defined carriers Cell coverage is unchanged
Cell range
Static Allocation
For internal use
Benefits
Capacity Enhancement : More CS and PS connections can be
served
Coverage Enhancement : More distant and weak CS&PS connection
can be served
Cost saving: Needed less radio modules for almost same DL
coverage
Implementation
Step 1 : RG301555 Higher average Power per TRX, Available in RG10
EP 5.1 and EX3.1, MP1,0
Step 2 : BSS21507 Flexible MCPA TX Power Pooling, Available in RG20
EP2 and BTS SW release : EX4.2
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
BCCH@20W
20W
20W
20W
20W
BCCH
20W
20W
SD/8
20W
20W
20W
20W
20W
20W
08W
20W
20W
20W
12W
8W
12W
12W
8W
20W
P0
Idle
Energy Optimized TCH Allocation to steer calls requiring max power
to BCCH TRX
Permanently Allocated BCCH Power
TRX2: Pmax=20W
TRX3: Pmax=20W
Admission Control to allocate the best possible channel with the
available MCPA power
Example of DL power levels usage on TS basis among TRXs
Instantaneous aggregate power not exceeding 40W due to use of DTX
& PC & Idle / Energy optimized
TCH Allocation feature reducing Pmax need
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
RG301555 : Higher Average Power per TRX (1/2)
This is the first step towards Dynamic Power Sharing in which the
gains of idle channels, DL Power control, DTX are utilised to
increase the average output power per TRX.
The BCCH Power is permanently allocated and the other TRXs use the
remaining pooled power
In case of temporary demand for high transmit power on all TCH
carriers TX power compression in BTS is done e.g. there is a lower
power used for the call than it comes from the Power Control
algorithm demand
Planned Configurations:
For internal use
Implications:
In case of many Distant & Weak connections (need full DL power)
the latest connection needs to be suppressed and may undergo
abnormal connection release
Try to avoid BCCH attenuation with this feature. Both still work,
but the full power of RM (=gain) is not available.
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
RG301555 : Visibility to BSS Level KPIs
Calls density will increase with the increase in coverage (weaker
connections can also be served) or capacity (busy hours volume
increase)
Calls performance will remain unchanged until high load appears,
then slight degradation may be observed for a single connection
that undergoes suppression
Calls abnormal releases unchanged until high load appears, then
slight increase will be observed
Once this feature has been implemented and simulated average busy
hour traffic profile is taken, the KPI changes can be provided. Now
only the theory about changes can be presented here
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
This feature introduces Admission and Congestion control algorithms
in BSC
Users with different DL power needs are allocated the most optimum
TCH within a cell so that the max TX power of MCPA is not
exceeded
In case that BSC overbooks power BTS uses an algorithm to compress
power of the mobiles so that power can be kept in the limit
In case higher power is needed of ongoing call, BSC performs
intracell handover to make sure that total MCPA TX power is not
exceeded
Supported Configurations
For internal use
BSS21507 : Flexible MCPA TX Power Pooling (2/2)
In case of many distant &weak connections (need full DL power)
all or several the adjacent connections (reside on same pipe and on
the same timeslot) may need to be equally suppressed and may more
rarely undergo abnormal connection release
Try to avoid BCCH attenuation with this feature. Both still work,
but the full power of RM (=gain) is not available.
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
BSS21507 : Flexible MCPA TX Power Pooling (2/2)
In case of many distant &weak connections (need full DL power)
all or several the adjacent connections (reside on same pipe and on
the same timeslot) may need to be equally suppressed and may more
rarely undergo abnormal connection release
Try to avoid BCCH attenuation with this feature. Both still work,
but the full power of RM (=gain) is not available.
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
Other Related Features
BSS20958 Energy Saving Mode for BCCH TRX
Reduces electricity consumption by reducing the transmit power of
the BCCH TRX
The dummy bursts on idle circuit switched channels of the BCCH
carrier are transmitted at 2 dB lower power level
Additionally, the feature enables a 2 dB dynamic power control on
active dedicated circuit switched channels of the BCCH TRX.
This saved power can be used with the Flexible MCPA TX power
pooling feature in other TRXs than BCCH TRX
BSS21222 Energy Optimized TCH Allocation
This feature steers the users requiring higher DL power to BCCH
TRX
This means that MS requiring higher DL power is served by BCCH TRX
and the remaining users for TCH TRXs may not need higher DL power
resulting in better KPIs
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
For internal use
System Module structure has internal redundancy - single failure
does not necessary bring the whole System Module down
High Power Amplifier efficiency and high RF integration level lead
to low power consumption and low heat dissipation, resulting
improved reliability due to lower operating temperatures inside the
RF Module and Remote RF Head (RRH)
Maintenance is improved by module integration and automatic fault
detection procedures complemented by efficient recovery and remote
control features in the SW
Special attention has been paid to the Flexi SW start-up time,
which e.g. minimises downtime when a new SW package is taken into
use
Several modules in Flexi Multiradio BTS site are the same as with
Flexi EDGE and Flexi WCDMA BTS, e.g. Flexi Power and Battery
back-up Module, thus bringing spare parts synergies among Flexi
platform products
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
System Module Redundancy
Baseband (BB) capacity in the System Module is implemented as a
resource pool consisting of three BB sub-assemblies
Each BB sub-assembly act as a redundant resource in case of a
failure of one.
System Module is able to maintain traffic with limited capacity in
case of BB sub-assembly, RF Module or fan failure.
Redundancy in fan modules ensures a proper operation in case of a
fan failure
RF Module Redundancy
1 RFM has 3 Tx chains and three separate PA modules. Failure of one
Tx chain may causes a reduction in capacity but does not cause a
total loss of service
RX-diversity provides redundancy for the receiver and the radio
remains operational though the other receiver within a branch is
down.
For configuration involving more than 1 RFM, the cell is spread
over two or multiple branches in two or multiple radios. In case of
failure of any branch, the radio control channels can be moved to
another branch in case of a failure.
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
RP3 redundancy
It is possible to have separate RP3 connection to the radio from
both GSM and WCDMA system modules in concurrent operation.
If one RP3 connection is cut, at least one technology remains
operational and there is not a total loss of service
If both the system modules are chained and RP3 -1 capacity allows,
both the technologies can remain operational
Flexi Power Supply redundancy
Flexi Power supply Module is compact and modular AC/DC and battery
backup unit with 4 sub-module slots for:
1…4 x 1kW rectifier
1…3 x Lithium-Ion battery
Power supply Module with 1...3 rectifiers is able to support N+1
redundancy
Flexi Power Supply
For internal use
Example: RF Module Redundancy for cells spread over two or multiple
MCPA Branches
Sector 1
Sector 3
Sector 2
Sectors spread over two MCPA Chains
Failure of 1 TX chain does not result in loss of service.
The control channels are automatically reconfigured to the other
branch in case of a failure
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
Improved cooling with Fans
Failure rate of a component depends exponentially on the the
temperature which the component has (Arrhenius equation)
Fans ensure that component temperature can be kept almost constant
for a wide environmental temperature range this maintaining almost
the same reliability
RF/System/Power Supply module controls the fan speed according to
the temperature information measured by sensors inside the
module
Fan unit contains two redundant fans enabling module operation at
normal temperatures, even with one fan (max. 30°C/86F)
Field MTBF for fan unit is currently > 4,000,000 Hours (465
years). Fans are field replaceable
Operating temperature
For internal use
Flexi Multiradio BTS
The radio technology is changed from single carrier power
amplifiers to multi carrier power amplifiers (MCPA).
No legacy antenna combiners are needed to combine the different TRX
outputs to a common antenna line.
Baseband processing is now centralized to the system module instead
of distributed to the radio modules as in Flexi EDGE BTS.
The interconnection between the system module and the radio module
is changed from Ethernet based electrical connection as in the
Flexi EDGE BTS to optical OBSAI connection as in Flexi WCDMA
BTS.
The Flexi Multiradio Supports Feederless sites without optical
optional converter modules.
Key differences: Flexi Multiradio BTS vs. Flexi EDGE BTS
* © Nokia Siemens Networks Flexi Multiradio BTS/Network
Engineering
For internal use
GSM
Channel
Numbers
3GPP
operating
band
Duplex
distance
FXCA
850MHz
FXFA
1900MHz