Exar offers an integrated monolithic solution to address desynchronisation requirements when mapping/demapping from SONET/SDH (synchronous) to DS3/E3 (asynchronous) environments. This unique desynchronisation solution will be embedded in Exar's physical interface (LIU) and data aggregation devices. The first data aggregation device utilising this capability was the company's OC-12 mapper (XRT94L43) announced last October. This new LIU is a single-channel DS3/E3/STS-1 device offered in two modes: one with desynchronisation (XRT75L00D), and the other with jitter attenuation only (XRT75L00). The devices use an innovative combination of analog and digital signal processing technologies to achieve their results. Applications include access equipment, digital cross-connect systems, routers, and digital subscriber line access multiplexer (DSLAMs).
Why does the clock need desynchronisation?
The process of mapping and subsequent de-mapping of individual DS3 or E3 signals into SONET's Synchronous Payload Envelope (SPE) introduces excessive jitter and timing irregularities. Examples of jitter sources include mapping jitter, caused by bit justification, or stuffing, to match the asynchronous bit rate to a synchronous transport signal; and pointer jitter, the outcome of frequency mismatches between two networks that offset the payload and cause pointer movement.
Discrete desynchronising solutions use a combination of a very narrow-bandwidth crystal oscillator based phase locked loop (PLL) referred to as a voltage control oscillator (VCXO), and a deep FIFO for each data rate and channel. In multi-channel and multi-rate applications, external VCXOs are multiplied by the number of supported rates and channels. Exar's solution uses only one highly integrated programmable PLL so each channel can support multirate (DS3, E3 or STS-1) operations.
Here jitter/timing irregularities are removed, and then desynchronised to provide a smooth GR-253-CORE specification-compliant clock signal. Once this operation is complete the signal is suitable for retransmission and returned to the data stream.
The XRT75L00 and XRT75L00D incorporate an independent receiver, transmitter and jitter attenuator in a single 52-pin TQFP package.
For further information contact Kobus van Rooyen, ASIC Design Services, 011 315 8316, [email protected]
Full sensor to cloud solution CST Electronics
Telecoms, Datacoms, Wireless, IoT
NeoCortec has demonstrated the seamless and rapid development of full sensor-to-cloud solutions using NeoMesh Click boards from MikroE and the IoTConnect cloud solution from Avnet.
Read more...Long-range Wi-Fi HaLow module TRX Electronics
Telecoms, Datacoms, Wireless, IoT
One of Mouser’s newest products is the Morse Micro MM6108-MF08651-US Wi-Fi HaLow Module, which adheres to the IEEE 802.11ah standard.
Read more...Quectel launches 3GPP NTN comms module Quectel Wireless Solutions
Telecoms, Datacoms, Wireless, IoT
Quectel Wireless Solutions has announced the Quectel BG95-S5 3GPP non-terrestrial network (NTN) satellite communication module.
Read more...SIMCom’s A7673x series Otto Wireless Solutions
Telecoms, Datacoms, Wireless, IoT
SIMCom recently released the A7673X series, a Cat.1 bis module based on the ASR1606 chipset, that supports wireless communication modes of LTE-FDD, with a maximum downlink rate of 10 Mbps and a maximum uplink rate of 5 Mbps.
Read more...Long-range connectivity module Avnet Silica
Telecoms, Datacoms, Wireless, IoT
Digi XBee XR 868 RF Modules support the deployment of long-range connectivity applications, and support point-to-point and mesh networking protocols.
Read more...4G LTE-M/NB-IoT connectivity reference design iCorp Technologies
Telecoms, Datacoms, Wireless, IoT
Developed around the industry-leading Nordic nRF9160 module, the platform comes complete with a newly-developed LTE antenna, ATRIA, which is pre-certified to operate over the full LTE-M and NB-IoT bands.
Read more...PolarFire SoC Discovery Kit ASIC Design Services
DSP, Micros & Memory
By offering a user-friendly, feature-rich development kit for embedded processing and compute acceleration, Microchip is making emerging technology more accessible to engineers at all levels.
Read more...Antennas to meet all connectivity requirements Electrocomp
Telecoms, Datacoms, Wireless, IoT
Kyocera AVX RF antennas meet today’s connectivity demands in the LTE, Wi-Fi, Bluetooth, GNSS, and ISM wireless bands, available in surface mount, patch or external configurations.
Read more...Introducing SIMCom’s new A7673X series Otto Wireless Solutions
Telecoms, Datacoms, Wireless, IoT
SIMCom recently released the A7673X series, a Cat 1 bis module that supports LTE-FDD, with a maximum downlink rate of 10 Mbps and an uplink rate of 5 Mbps.
printer friendly version