BSS_1
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Transcript of BSS_1
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BASE STATION SOLUTIONS
Rakon Limited
(Corporate Head Office)
Phone: +64 (9) 573 5554
Fax: +64 (9) 573 5559
Email: [email protected]
Rakon Europe Limited
(Europe, Middle East, Africa)
Phone: +44 (1522) 883500
Fax: +44 (1522) 883524
Email: [email protected]
Rakon Taiwan
Representative Office (Asia)
Phone: +886 (2) 2759 0259
Fax: +886 (2) 2759 2668
Email: [email protected]
Rakon Limited Shenzhen
Representative Office (China)
Phone: +86 (755) 8283 5991
Fax: +86 (755) 8283 5990
Email: [email protected]
Rakon America LLC
(Americas)
Phone: +1 (847) 930 5100
Fax: +1 (847) 844 3236
Email: [email protected]
www.rakon.com
The evoluon mobile phones as Personal Communicaon Devices and the explosion of devices such as tablets have created a
challenge for the mobile networks, starng from the Base Staon and the Mobile Backhaul. New iniaves such as Small Cells
reduce the pressure of capacity crunch and coverage limitaons, but the importance of Macro Base Staons remains very high.
With the transion to the packet based backhaul mechanisms, the synchronizaon implementaons have become extremely
challenging.
Introduction
Tradionally Base Staons were connected to the core networkthrough circuit switched network connecons delivering data
and the frequency synchronizaon. When Phase informaon
was required because of the air interface requirements, a
GPS based system was used and a combinaon of GPS and
line extracted frequency were used for synchronizing base
staons. We can generalize the requirements to network
side requirements and radio side requirements. The network
recovered clock had to meet the limit of 16ppb to the network
and the air interface had a frequency accuracy requirement of
50ppb and phase accuracy requirement of few S whenever
required. The 16ppb requirement is derived from the Stratum
2 frequency accuracy levels of and in a scenario where the
network or GPS synchronizaon were lost, the base staon be
able to maintain its accuracy within the air interface limits.
Base Station Synchronization Challenges
BTS Type
Applications
MacroGSM
Macro & Wide Area
CDMA2000, WCDMA-FDD/TDD, TD-SCDMA
LTE - FDD, LTE - TDD
Wide Area and Home
Frequency 16 to 50 ppb 16 to 50 ppb 16 to 50 ppb
Time / Phase None 1.5 to 10 s None or up to 32 s
OCXO Mercury ROX2522S4 ROX None or up to 32 s
Base Station Synchronization Requirements
The challenges in Macro Base Staon Synchronizaon are mulfold. GPS or other GNSS methods are no longer preferred as a
primary source of network ming because of the fear of signal
loss or jamming in various situaons. Secondly, the circuit switch
network is transioning to packet switched network forcing the
Base Staons to use Synchronous Ethernet and Precision Time
Protocol based synchronizaon techniques. ITU-T has finalized
the standards for frequency only Packet Equipment Slave
Clocks and are working to finalize the network and equipment
requirements for phase and frequency. Many implementaons
are relying on a combinaon of GNSS and packet clock methods
to achieve the synchronizaon requirements.
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BASE STATION SOLUTIONS
Rakon Limited
(Corporate Head Office)
Phone: +64 (9) 573 5554
Fax: +64 (9) 573 5559
Email: [email protected]
Rakon Europe Limited
(Europe, Middle East, Africa)
Phone: +44 (1522) 883500
Fax: +44 (1522) 883524
Email: [email protected]
Rakon Taiwan
Representative Office (Asia)
Phone: +886 (2) 2759 0259
Fax: +886 (2) 2759 2668
Email: [email protected]
Rakon Limited Shenzhen
Representative Office (China)
Phone: +86 (755) 8283 5991
Fax: +86 (755) 8283 5990
Email: [email protected]
Rakon America LLC
(Americas)
Phone: +1 (847) 930 5100
Fax: +1 (847) 844 3236
Email: [email protected]
www.rakon.com
Rakon Oscillators for Base Station Timing applications
Two main aspects of the oscillators are considered for Base
Staon synchronizaon designs. The holdover requirement
is one of the primary objecves. The service impact on the
service provider is the turnaround me to aend to and
repair the systems, if anything were to disturb synchronizaon
mechanisms. Holdover me is required by the operator so
that they system remains operaons within the me limit in
which it can be aended to. Depending on the air interface
requirements, constraints may be placed on frequency only or
frequency and phase to achieve certain holdover me periods.
In a synchronizer design, the holdover me depends on the
oscillator, specifically on the frequency versus temperature
characteriscs and the slope performances of frequency
with temperature. Secondly, Packet based networks impose
extremely low bandwidths on clock recovery PLLs, due to the
varying nature of PDVs. Depending on the loop bandwidth,
very stable oscillators (MTIE and TDEV on such bandwidths) are
required for implementaon of such PLLs. Oscillator selecon
is carefully done idenfying the holdover and loop bandwidth
requirements, along with other consideraons such as phase
noise.
Rakon XO, Crystal
Rakon TCXO Rakon VCXO
Rakon OCXO
Network Interface
(16ppb accuracy)
GPS Module
(1pps, 1s accuracy)
Modem
(Time & Synchronizaon,
G.812, G.8262, IEEE1588
Timing)
Radio Interface
(50ppb, 1s accuracy)
Product
Family
Product
Series
Key
Capabilities
TCXO IT 10 to 50 MHz, 0.5ppm frequency stability over -40 to 85C in 3.2x2.5, 2.5x2.0 or 2.0 x 1.6mm packages.
VCXO RVX-M10 to 460 MHz, high frequency with low phase noise and CMOS/LVPECL/LVDS in 7.0 x 5.0, 5.0 x 3.2 mm
package.
XO RXO-M10 to 460 MHz, high frequency with low jitter and CMOS/LVPECL/LVDS in 7.0 x 5.0 or 5.0 x 3.2 mm
package.
CrystalsRSX 10 to 50 MHz, 10ppm frequency stability over -40 to 85C in 3.2x2.5, 2.5x2.0 or 2.0 x 1.6mm packages
RTF 32 kHz for real time clocks.
Frequency Stability Holdover Stability Frequency Ageing
ROX-T1/T2Statum 2
