You are on page 1of 3

Research Paper Engineering Volume : 3 | Issue : 4 | April 2013 | ISSN - 2249-555X

Control Command for Microwave Link
Acknowledgment and its Troubleshooting Strategy

Keywords Microwave Communication, NEC Microwave, Microwave Acknowledgment and Troubleshooting

Mohd Aamirullah Inamdar Dr. Sayyad Ajij D
Badi Masjid Campus (B.M.C), R.No:-06, HOD of Electronics & Communication, Engineering
Opposite Osmanpura Post Office, Osmanpura, department, MIT College, Beed Bypass Road
Aurangabad-431005. Aurangabad-431028.
ABSTRACT Initially NEC (Name of company) Microwave manufacturing, Japan is introduced briefly and then various ac-
knowledgments and there different troubleshooting methods. The flow chart to reduce the time of doing trou-
bleshooting is explain. The main objective is to reduce the call drop of TATA DOCOMO and to overcome the drop if occur
within short duration of time. There exists limited literature on NEC microwave, especially with regard to acknowledgments
and troubleshooting. The working of NEC microwave, classification & tools on the basis of the NEC equipment used in TATA
DOCOMO & flow chart to reduced the time is described. According to different types they produce different acknowledgment
and depending upon the acknowledgment the troubleshooting strategy changes.

1. INTRODUCTION: more useful for TATA. The following numbers of operators
Today wireless technology is used in many applications well are using NEC
integrated into our everyday life. Planning a good, stable and
reliable microwave network can be quite challenging. Careful Ø TATA DOCOMO
planning and detailed analysis is required for a microwave Ø Reliance
radio system before the equipment can be installed. A poorly Ø Idea
designed path can result in periodic system outages, result- Ø Airtel
ing in increased system latency, decreased throughput, or Ø Aircel
worst case, a complete failure of the system. It is generally
agreed that a microwave signal is a signal whose fundamen- Only Vodafone and BSNL is not using this equipment they
tal frequency is between 300 MHz and 300 GHz [1, 2]. In are using NOKIA, but it will be helpful for NOKIA employee
terms of wavelength, a microwave signal has a wavelength also for their troubleshooting method [5].
between 0.1 cm and 100 cm A the waveguide is a hollow
mechanical structure that permits propagation of microwave
signals from one point to another with the least possible loss.
Most commonly used waveguides are those having a rec-
tangular form. There are, however, a variety of rectangular
waveguides, each being identified according to its internal
dimensions. Each type of waveguide allows microwave prop-
agation within a particular frequency band [3]. Discussing all
the acknowledgment present in working link of NEC micro-
wave and there trouble shooting methods. Figure 3.1 NEC microwave communication system

1. SDH(Synchronous Digital Hierarchy)
2. PDH (Plesuchronous Digital Hierarchy)

SDH: Pasolink+ STM1, Pasolink Neoi
PDH: Pasolink CPV, Pasolink V4s

Fig 3.1 shows the Transmitter converts the source message
into an electrical signal. The Transmitter is basically respon-
sible for encoding the message and then this encoded mes-
sage is multiplied by carrier frequency i.e. modulate the
signal and then over the channel. At the receive end, the
receiver demodulate the received signal and decode it and
generate the original message. Minimal distortion at the re-
ceiver end is referred as a good communication property [4].
Fig.3.2 is the general flow chart, which can be used for any
equipment (Other then NEC) & for any operator (Other then
TATA), the main aim of this flow chart is to reduce the call
drops of any operators, and if drop occurs how to overcome Figure 3.2 Flow chart of trouble shooting Method.
the drop within very small time spectrum. First stage (Start-A)
are written to avoid the call drops, from second stage (A-End) 4. TOOLS:
if call drop occurs how to overcome that drop is mention, The following tools are used in NEC Microwave
because many operators are using NEC equipment In mi-
crowave that’s why it will be helpful to that operators, near 1) Software Tools
about four operators are dependent on TATA that’s why it is 2) Hardware Tools


ticeable effect on the overall system However if noise can be detected. Ø EARLY WARNING Ø FRAME ID 2) Description Ø LOF As shown in figure 5.when signal to noise ratio decreases it tends to The PNMT is used for the commissioning of Passo+/ increase in BER and due to increase in bit error rate high BER Passo V4 IDU. The PNMSj is used for the When all this alarm comes together then it means there is a observation of all the types of NEC microwave from the major chance of interference or misalignment server. in LOF when we transmit signal does not Ø LCT for CPV reach at the receiver end and return to the transmitter. RX Level:. Research Paper Volume : 3 | Issue : 4 | April 2013 | ISSN . Frame ID: . If the medium between the transmitter and receiver is good and the signal to noise ratio is high. LCT for STD is used for commissioning of NEOi IDU and LCT for CPV is used for Troubleshooting commissioning of NEO/ic IDU. any other radio. disconnect pow- 2) Hardware Tools:-Three hardware are used in this. Ø PNMT LOF(Loss Of frame):.when the RX level reduces from their to be considered. When all this alarm comes together then it means there is a crement in BER creates complications in link. then the bit error rate STM-1(1)(DMR):. if RX level is coming in the range of -99 to -80 dbm at both the end then there is no interference) Ø IDU Ø ODU Acknowledgment 1 [8. avoid the interference in between the two link) this alarm is ware is used for observing all the sites from the server. the de.1 Acknowledgment 1 5.when any tree. the upper band is having more TX frequency then the TX of lower and the RX of upper is the TX of lower and vice versa.2 In this following alarm are observed Ø HIGH BER Ø RX Level Bit Error Rate (BER) is the percentage of bits that have errors Ø LOF relative to the total number of bits received in a transmission.Four software’s are used for commis. Ø PNMTj etc comes in between the two microwave of single link then Ø LCT for STD this alarm will appear.It act as transmitter which can transmit and receive the microwave signals. of NEOi/Neo/ic in working link.when there is no transmission through opti- will be very small . it is notified that the continuous in. It is of two types upper band & lower band. power of ODU for microwave link.000 bits transmitted. ODU (Out Door Unit):.possibly insignificant and having no no. DESCRIPTION OF ACKNOWLEDGMENT AND THEIR TROUBLESHOOTING METHODS If Interference:.(It is the application which is inserted by NEC to sioning of different types of NEC microwave and one soft.when there is any frame loss takes place then this alarm BER = number of errors / total number of bits sent will appear.7] limit after 15 mints this alarm will appear.we need to change the frequency & frame 1) Description ID at both the end As shown in fig 5. It is also used for observ- ing the alarms in working Link. Early Warning: .9] Ø Antenna IDU (In door Unit):. stage of BER.This alarm is generated when receiving level de- The definition of bit error rate can be translated into a simple creases from its limit.It is used for the allowing the differ- ent frequency and power for getting the maximum receiving power. At the starting major chance of power failure at far end. a Ø TCN-RX LEV-15min transmission might have a BER of 10 to the minus 6.It is used for the assigning the frequency.This alarm is generated due to the increase Troubleshooting in Bit Error Rate (BER).2249-555X 1) Software Tools:. (To check whether interference exist or not. Ø PNMSj High BER:. then there is chance that the bit error rate will need TCN-RX LEV-15min:. meaning that. PNMTj is used for observing the alarms is generated. building.We need to make the proper alignment at both the ends. details are as follows If misalignment:. Figure 5. it generates early warning alarm and a incre- ment of BER results in following alarms The power failure may occurs due to following reasons Ø Low BER Ø MCB Trip Ø High BER Ø NO Power Supply Ø DEM Alarm Ø IDU Faulty INDIAN JOURNAL OF APPLIED RESEARCH X 169 . Antenna:. The generated when there is mismatch of frame ID between the details are as follows. one bit was in error. Ø STM-1(1)(DMR) usually expressed as ten to a negative power. er supply at one end and check the RX level at other end and tails are as follows vice versa. two sites of single link. cal port then this alarm will appear. out of 1.000.1 In this four alarms is generated. formula: LOF:. For example. [6.

Hall. “Analysis And Planning Microwave Link To Established Efficient Wireless Communications”. | 9. “Basic Path Considerations for A Microwave Link”. . Sanjeeva Gupta. Due to minimization of microwave error signal we can improve the quality of microwave signal and reducing the call dropping between caller and callee. Deon Reynders [Online Book]. 170 X INDIAN JOURNAL OF APPLIED RESEARCH . 1957. H. 1999. Telecom Regulatory Authority of India. William Stalling. Prentice. EM Clarity White Paper. F. Molinaro.Then either change the MCB or repair the Acknowledgment 2 MCB If No power Supply:. Practical telecommunications and wireless communications for business AvEdwin Wright. May 2010. Microwave Engineering. “Fundamentals of Radio Link Engineering”. 2nd ed. Research Paper Volume : 3 | Issue : 4 | April 2013 | ISSN . Japan. | 3. Rakib Al Mahmud.2005 | 8. April 2003. Abdullah Jr. | 5. Md. L Bermudez. by providing the proper trouble- shooting command action with respective to the feedback error signal. | 4.Make the arrangement of power supply If IDU faulty:. Figure 5.2 Acknowledgment 2 REFERENCE 1. we have reduced the microwave acknowledgement with the particular alarm at particular frame. J. Website of NEC Corporation. Carlos Evangelista. | 2.2249-555X If MCB is Trip:. “Tools For Microwave Radio Communications System Design”. Luis. Conclusion By the sanctity of caller and callee voice information. McGraw-Hill | 7. Frank Jimene.please check the power card if not working change the power card and if it may creating problem the changed the complete IDU. “Wireless Communications & Networks”. | 6. September 2009. Paulo Carvalho.