Albedo AT-2048 Installation And Maintenance Manual Download Page 1 | Manualshive

Page: 1 / 32

Albedo AT-2048 Installation And Maintenance Manual Download Page 1

(C) ALBEDO TELECOM - 2010

Installation and Maintenance of E1 circuits

ALBEDO AT-2048 is a rug-

ged fully featured battery oper-
ated E1/Datacom handheld
tester designed in 2010 provid-
ing easy navigation and high
resolution screen. Low cost, fully
featured, it is a truly perfect field
tool for installation, acceptance
and maintenance of PDH and
Datacom links including bi-di-
rectional (BER) test functions.

A valuable tool that offers

generator, dual analyzer, USB,
Ethernet, and RJ45 interfaces. It
offers Jitter measurements and
pulse mask, therefore it can
monitor slots activity, delay and
frequency measurements fre-
quency measurements over
more than seven hours. Test re-
sults can be saved in a Memory
stick or transferred to a PC.

1
2
3
...
»

Summary of Contents for AT-2048

Page 1: ...y perfect field tool for installation acceptance and maintenance of PDH and Datacom links including bi di rectional BER test functions A valuable tool that offers generator dual analyzer USB Ethernet...

Page 2: ...its final destination In this primitive system we can already identify all the elements of a genuine communications network see Figure 2 Information consists of the messages interchanged between fina...

Page 3: ...ee Table 1 1 Analog or continuous They can take any of an unlimited number of values within a given range 2 Digital or discrete They can only take a limited number of values In a binary system the onl...

Page 4: ...in which the information is transmitted in the form of radioelectrical or optical signals for example the atmosphere and optical fiber Transmitted signal Attenuation Distortion Noise Received signal...

Page 5: ...e 3 Transmission media can usually be characterized by their attenuation per unit of length AdB Km Example Thus for a transmission medium with A 0 2 dB Km after 15 Km the at tenuation is AdB 3 dB If t...

Page 6: ...on sometimes called dispersion Delay distortion is particularly disturbing in the digital transmission producing intersymbol inter ference ISI where a component of the signal of one bit is misplaced i...

Page 7: ...mospheric noise This is caused by the static discharge of clouds or ionized gas from the sun or high frequency signals radiated by the stars 4 Impulse noise Of short duration but high amplitude these...

Page 8: ...an be transmitted across a line or a network Data rate expressed in bits per second bit s This is a measure of the speed with which information is transferred It depends on the bandwidth transmis sion...

Page 9: ...eceiving end There are a number of different line codes that apply to digital transmission the most widely used ones are alternate mark inversion AMI high density bipolar three ze ros HDB3 and coded m...

Page 10: ...ight or more consecutive ze ros The objective is to ensure a sufficient number of transitions to maintain the synchronization when the user data stream contains a large number of consecutive zeros see...

Page 11: ...MI coding and de coding circuits compared to the HDB3 for these rates In this case a 1 is transmit ted according to the AMI rule of alternate polarity with a negative level of voltage during the first...

Page 12: ...ology and is based on artificially increasing the bandwidth of the signal according to a predefined pattern 4 Polarization division multiple access PDMA Given that polarization can be maintained the p...

Page 13: ...h the arrival of digital sys tems in the 1960s when improving the performance of communications networks became a real possibility However this technology was not completely adopted until the mid 1970...

Page 14: ...alog signal every 1 fs seconds the sampling period 2 Quantization assigns these samples a value by approximation and in accor dance with a quantization curve i e A law of ITU T 2 3 Encoding provides t...

Page 15: ...rst digital communications system was set up by Bell Labs in 1962 and consisted of 24 digital channels running at what is known as T1 fs 2 4 000 8 000 Hz T 1 8 000 125 s v 8 000 samples s 8bits sample...

Page 16: ...gnaling the rest were as signed originally for voice data transport see Figure 12 The main characteristics of the 2 Mbit s frame are described in the following 4 1 Frame Alignment In an E1 channel com...

Page 17: ...d8 a8 b8 a23 b23 c23 d23 0 1 C1 0 1 0 1 1 8 Time Slot 0 1 15 Time Slot 16 17 31 125 s Submultiframe I Submultiframe II 2 ms Channel 1 15 16 30 Remote Alarm Indicator Channel CAS Bits Alignment Bits CR...

Page 18: ...reason a CRC 4 multiframe alignment word is needed Obviously the receiver has to be told where the multiframe begins synchronization The CRC 4 multiframe alignment word is the set combination 001011 w...

Page 19: ...ission quality without disturbing the information traffic and when this quality is not of the required stan dard taking the necessary steps to improve it Telephone traffic is two way which means that...

Page 20: ...TS0 is used to indicate that an alarm has occurred at the far end of the communication When operating normally it is set to 0 while a value of 1 indicates an alarm The bits in positions 4 to 8 are spa...

Page 21: ...mation can be transmitted by two differ ent methods the common channel signaling CCS method and the channel associ ated signaling CAS method In both cases the time slot TS16 of the basic 2 Mbit s fram...

Page 22: ...ecutive E1 frames 4 8 1 CAS multiframe alignment signal In order to synchronize the CAS multiframe that is to identify where it begins a multiframe alignment signal MFAS is defined made up of the sequ...

Page 23: ...n it receives this indication of loss of multiframe alignment at the far end the near end multiplexer sends a signal made up entirely of bits at 1 known as AIS64 alarm indication signal 64 kbit s in t...

Page 24: ...fter two consecutive frames with the MRAI bit equal to 1 ITU T G 732 CAS MAIS Channel associated signaling multiframe alarm indication signal It is detected if there are less than three zeros in the t...

Page 25: ...data Group IV contains a block of four J bits a block of R bits justification oppor tunity one per tributary and 204 T bits To check whether R bits have been used the J bits are analyzed in each of t...

Page 26: ...1 T2 T3 T4 T1 T2 T3 T4 1952 1465 J1 J2 J3 J4 T1 T2 T3 T4 T1 T2 T3 T4 2440 1953 T1 T2 T3 T4 T1 T2 T3 T4 T1 T2 T3 T4 T1 T2 T3 T4 J1 J2 J3 J4 T1 T2 T3 T4 T1 T2 T3 T4 T1 T2 T3 T4 385 768 J1 J2 J3 J4 T1 T2...

Page 27: ...down conditions are detected in the near end device The spare bits are designed for national use and must be set to 1 in digital paths that cross interna tional boundaries 5 6 Plesiochronous Synchroni...

Page 28: ...ing bit or justification bit called justification opportunity in the output aggregate signal Its task is that of adapting the signal that enters the multiplexer to the rate at which this signal is tra...

Page 29: ...in the frame Each group of control bits refers to one of the tributaries of the frame All of them will be set to 0 if the associated opportunity bit is carrying useful information oth erwise they will...

Page 30: ...140 Mbit s frames enables the multiplexers that correspond to these hierarchies to transmit alarm indications to the far ends see Figure 22 when a multiplexer detects an alarm condition see Table 4 In...

Page 31: ...tics of hierarchical digital interfaces ITU T Rec G 704 10 98 Synchronous frame structures used at 1 544 6 312 2 048 8 448 and 44 736 kbit s hierarchical levels ITU T Rec G 742 11 88 Second order digi...

Page 32: ...lth of Network Architectures Service Agreements SLA IP Quality QoS or fix any issue Your Business Partner Results ALBEDO Telecom helps the industry to make the most of the investment on infrastructure...

Reviews:

No comments