1. Table of contents -> Overview of the organization -> plan of internship programmme -> Training programme -> Conclusion -> Recommendation -> References and Resources Overview of the organization :- Pakistan Telecommunication Company Limited (PTCL) is a mega corporation and a leading telecommunication authority in Pakistan. The corporation provides telephonic and internet services nation-wide and is the backbone 2. for country's telecommunication infrastructure despite arrival of a dozens other telecommunication corporations, including Telenor Corps and China Mobile Ltd. The corporation manages and operates around 2000 telephone exchanges across the country, providing the largest fixed line network. Data and backbone services such as GSM, CDMA, Broadband Internet, IPTV, wholesale are an increasing part of its business. From the of beginning Posts & Telegraph Department in 1947 and establishment of Pakistan Telephone & Telegraph Department in 1962, PTCL has been a major player in telecommunication in Pakistan. Despite having established a network of enormous size, PTCL workings and policies have attracted regular criticism from other smaller operators and the civil society of Pakistan. Now as hierarchy of organization is concerned that our main exchanges such that DHA , thokar and GOR all are connected to BSc through fibre where as the other local sites nearby to DHA (super town, farkhanda, DHA phase-1) are connected to DHA through PTMP, which i'll explain later in my report. And in the cantt exchange the number of employees are such that there are two teams which are working in field. each team consists of an engineer, two technitions and a driver. And there is an engineer in the office which manages store room for the field engineers, and the responsibility of that engineer is to make sure that a particular equipment is available in the store room when available and he also has to perform official work as well. And there are two SE (senior engineers). if a fault is out of engineer's hand then SE will fix that fault. And in NMS there are three persons who are doing thier duties in thier respective slots. one form 8:00 am to 2:00 pm, 2nd one is from 2:00 pm to 8:00 pm and 3rd one is from 8:00 pm to 8:00 am and thier supervisior in NMS is also an engineer so this is how the our team in cannt branch operates. And The hirarchy of our communication is such that our BTS is connected to BSc and BSc is further connected to MSc. our MSc has to perform three task. 1) Alarm generation 2) call tracing 3) some number off or block And there are total 16 MSc in pakistan in which one is in PTCL cantt branch. e.g agencies and police headquaters will contact MSc if they have to trace a call. And whenever you buy a EVO usb or any other modem related to the PTCL, there is a bar code which is required for the registration when you start using that device so there is a pakage called as "WIN + AAA" in which AAA is for the authentication purpose for the device, and WIN is basically a user tariff.so PTCL gulberg branch is the only branch in pakistan which is controlling 3. this "WIN +AAA" pakage. Plan of internship programme :- I worked in the wireless department and attached with the unit of NMS WLL/MSc. The exchange of PTCL in which i worked is in cantt and this exchange is dealing with the fault detection and maintainance of BTS and tower. The other exchange is in Garden town . And there are basically three regions in Lahore. PTCL cantt branch is dealing with the north and south regions and garden town branch is dealing with all the central sites. My internship started at 15-7-2013 till 25-8-2013 so it was a 40 days internship programme in which i worked with NMS and also work with BSS. wireless department is a department which demands duty round the clock so an engineer always have to prepare whenever there occurs some fault. And the efficiency of the field work is maintained through team work so in field team work is basically the key. while the importance of NMS cannot be neglected, because the person sitting in the NMS has to deal with the field engineer directly so he must know every bit about the software in order to develop a good communication between field workers and NMS. Training programme :- Field work :- Ist visiting day :- Our BTS operates on three things. 1) WAPDA 2) DG (generators) 3) batteries visited two different sites one at lower mall and other at ganga ram, at lower mall we changed the batteries placed 8 batteries (2 set of batteries) to make voltage of 48 (it almost maintains voltage of 53.5 V). each battery is of 100 ampare. At sites we use rectifires to convert AC into DC because our BTS operates on DC and also because it is more safe to work with DC instead of AC. furthermore rectifires serve for the purpose of charging. we also observed the PMU which is related to alarms which operates when there is a fault at site and send a signal to MSc which further send B.Sc to check that fault and to fix it. The hirarchy of our communication system is that our BTS in an area are connected to BSc and BSc further connected to MSc. and also there is a RRU which is related to rate of transmittion of a signal and has a particular value. 4. The booster has three antenas at its top which are maintained such that they cover angle of 360 degrees. and also the distance b/w two BTS should be not more than 2 km in order to transmitt signals accurately. BTS is base transceiver station. And A single BTS may contain 1 or 2 Radio Base Units (RBUs). Each RBU contains all necessary Transmit/Receive equipment required for the operation of a single sector or cell. RRU the Remote Radio Unit is a radio transceiver capable of handling multiple of 8 mobile subscribers calls. This is called RRU as this unit is generally installed in towers and are controlled by a controller placed inside a closed shelter on the ground nearby the tower. 2nd visiting day:- Visited johar town site and the nature of the fault was a radio fault and ODU of our dish was out of order due to the rain water so we replace the ODU of dish. And it was a good learning day. Our BTS operates on 48 volts. And the most important part of BTS is its master rack in which there is a PMU (power monitoring unit) which has all the alarms and it give B.sc signal in case it sense any change in temperature, humidity etc, also it alarms when our batteries back up is not sufficient to operate our BTS. One can say that PMU is the brain of BTS. Rectifieres are connected in the same cabinet after PMU. and in that cabinet we have different switches to on or off rectifiers and PMU. we use three rectifiers in that cabinet. but our BTS can also operate on one rectifier. the other two rectifiers work as a backup in case if any of the rectifier get out of order and also three rectifiers share the load of BTS. The batteries connected in the BTS should have a backup of 10 to 11 hours. although the load shedding time is just 2 to 3 hours maximum but in some case if our generator is not working ( fuel is less or any other problem), in that case batteries will work and our site will not be down until B.Sc send the concerned person to check that problem. and also the purpose of using both batteries and generators together is when light goes off generator will not start immediately it will take 2 to 3 minutes and we can't intrupt our communication even for 10 ns so in that 2 to 3 minute batteries will support our system. And the sites to which generator is not connected are known as "non DG" sites. now there is another cabinet known as IBAS shortly called as base station. although each site is connected to other site but IBAS is not only connected to other sites but it is acting as a server for 10 to 15 sites, means if server is down then all sites connected to it will be down. And IBAS is not present in every BTS, some particular BTS only and IBAS which is introduced by intracom can entertain 46 terminals (BTS). 5. adjascent to IBAS there is another rack known as IDU (in door unit) which is only connected one site to ather single site only. it has a cable known as IF cable. the one end of the cable is connected to this rack and the other end is connected to the ODU dish which is connected at the top of the booster. Now as the alignment of the dish is concerned, dish must be exactly aligned to its nearby booster. if there is a little bit of disalignment then our BTS will not recieve any information, and our site will give lots of alarms. now this problem is out of technition's hands. here comes engineer. And if you see multiple dishes connected to a booster then it is a sharing site means more then on companies share this site e.g ufone and PTCL are sharing thier sites now a days i.e same BTS will use to transmitt signals of both ufone and PTCL. Although an independent site may have two to three dishes. Actually the number of dishes, number of RRU and number of battery banks depends upon the number of subscribers (load) in that area. 3rd visitind day : if there are 3 RRU in a booster then we will use 3 battery bank. And if there are 6 RRU attached to a booster then we will use 5 battery bank.(A battery bank includes 4 batteries each of 12 V). A RRU includes a transmitter and a reciever. it will recieve and transmiit as well the high frequency signal, when a high frequency signal passes through it. it will heat up. In old BTS (3606), we used RRU at the base (in door RRU) so the disadvantage of using such a scheme was when RRU heated up so we have to use air-condiotioned or cooling fan to normalize its temprature which increased our cost and thus it was costly. so in new model (3900), we are using outdoor RRU at the top of booster. it is designed in such a way that it does not change the temprature level of RRU no matter how much frequency is passing through it. And also when we purchased a BSc from a company it will also give us some carriers lets suppose 650 carriers, but we don't use more than 600 carriers to avoid our BSc to be over- loaded but somehow if we managed to use 625 carriers and still we are in a need of more carriers then what we are doing, instead of purchasing a whole Bsc we purchase a tool which may be offering us 100 or 200 carriers so now we can facilitate more users. e.g a BTS having 12 carriers means that it has a frequency of 950 MHz (band width). similarly BTS having carriers 13, 14, 15 etc will have different frequencies. 4th visiting day :- During the inspection of a site, an engineer need to check the following things. RRU, sector antenas, GPS antena , Battery Bank , Rectifier , civil work (door lock, severage system , 6. garbage in room etc.) smart switch is basically use to on generators, when light turns off. Now a days we have a replacement of smart switch known as metro switch, this switch acts as relay when batteries maintains a voltafe of 48 V then it will cut load from batteries and convert it to generators. because now we are emphasizing to use both batteries and generators together rather using generators only. CDMA is known as "Code division multiple access", as its name suggests it is a example of multiple access which is where civil transmitters can send information simultaneously over a single communication channel. 5th visiting day :- Visited three different sites 1) shiekh zaid 2) tariq block 3) ataturq block CMPT has two functions. 1) it connects our BSc to BTS. 2) it provides a clock which will act as a on or off state. and if there is any fault in CMPT then BTS will dis-connect. and our BTS is also linked with satellite through GPS antena. PTCL operates on two different frequencies. 1) 450 MHz 2) 1900 MHz and theses frequencies are purchased by FAB (frequency allocation board). the 450 MHz frequency is usually used in rural areas because of its less frequency, the wavelength is higher so it can cover a huge area because in rural areas our number of users are not very large. and 1900 MHz frequency is used in urban areas where number of users are larger than rural areas so it will obviously cover less area to maintain a good and efficient service. 6th visiting day :- And the number of subscribers a BTS can entertain depends upon the channel processing chips which is present in CCPM (3606) or in HCPM (3900).these chips may be 3 or 4. And whenever there is a fault of Dish or its level is disturbed. so there is a software introduced by intracom which is used to check its level. this software has a window known as "SPU physical 7. characteristics", and it contains the information of downlink and uplink. its has the following parameters of a site such as 1) Distance in meter (distance of the exchange dish to local dish). 2) state 3) physical mode 4) downlink (Rx level , Rx C/N) 5) uplink (Rx level , Rx C/N) the downlink must be less than -60 and its ideal QAM should be 64. we will change the direction of dish(up, down, left,right) until the level gets down below 60. dishes are usually of different sizes. larger the size of a dish, larger will be its transmittion power. And there are two different types of radio transmittion 1) RTN which is PTP (point to point) made by huawei 2) PTMP (point to multi-point) made by intracom PTP as its name suggests is used to allign a dish with a singal dish, where as PTMP makes a loob on its either side and covers dishes may be 3 or 4 depends upon transmittion power of dish this is the advantage of PTMP that we dont need to lay down the fibre from exchange to other local sites.And if the allignment of dish is disturbed such that one dish gets out of its range then that site will be down and if two dishes gets out of range then 2 sites will be down and so on. and if a BTS has 12 carriers, it doesn't mean that it contains the 12 carriers, 12 carrier is just a name or its just a number which has a frequency of 950 MHz. 13 carrier number has frequency of 975 MHz and so on. and when u make a call through ur vptcl number to a person which may be in johar town or ichra or may be somewhere else, ur call will be connected through that area BTS and then to ur concerned person i.e only one BTS is involved in a phone call. Two BTS may be involved while travelling for example ur call is connected to one BTS and when u travel out of the region of that BTS then it will "hand off" ur call to the next BTS and your communication will not be disturbed. And when a new site is constructed then PTCL approach Huawei for this purpose. Hauwei further give this contract to venders which construct the whole BTS. and when a BTS is not on air (under construction), then at air bridge its name will be like "Test BTS" with a cross sign in its start. Experience with NMS :- 8. From BTS to BSc, two connections are possible. 1) one is physical connection.(through cable) 2) 2nd is radio connection.(RTN and PTMP(point to multi-point)) and BSc we use is: BSc 6680 made by Hauwei The software which we use to detect fault on the sites is Air bridge software. it has two windows:- 1) service maintainance system 2) Alarm managment system so in the first window all the site names are appearing with thier status for example a cross sign before a site indicates that this site is disconnected to BSc and a red sign indicates that there is a fault which is not of immediate concern but it must be fixed on priority basis. Now there are two types of BTS in the air bridge software. 1) DBS 3900 2) BTS 3606 (also there is two other models named as 3600 and 3606E). and also there are two types of services. 1) 1x service ( usually use for mobile phone calls) 2) EVDO service (use to facilitate evo service of PTCL). HCPM in the master rank entertains the 1x service while HECM entertains the EVDO service. And also there is a CMPT in the master rank which has two functions. 1) it provides connection between BSc and BTS. 2) it controls the whole BTS. And alarm generation system is called as UPEU system Rectifiers are also called PSU (power supply unit) because they are acting as power supply for the BTS ( provides the DC for BTS). and also there is a TCU in master rank which uses for cooling purpose. if we want to use any command in the air bridge. we will use LST or DSP in the start. e.g DSP 9. RES commands will show all the sectors of a BTS.And also in BTS name there is a number known as headquater ID, which is being assigned by the headquater to every BTS. and if it is a ufone sharing site then a ufone ID will be apperaing in the site name and if a BTS name is like "TEST BTS", then its mean that this BTS is under construction and is not on-air yet. Office work:- Manage data of all the sites, about PMU and PSU whether they are working or not and make a report of all that data and send it to the head quarter. Also manage the store room and make equipments available for the field engineer are basically the tasks of a an engineer. So basically an engineer must have the ability to fight with the other departments e.g. development, RF etc and make all the necessary equipments available in the time of need. And also if there is an issue while accessing a site like night time issue, guard issue, key issue etc so an office engineer has to make the report of all that access issues and send it to the concerned person. And there are many other official issues like meetings, visits and staff management which are the responsibility of an office engineer. Conclusion :- It was very good expierence of working with a nation wide telecommunication company and it gave me help to understand the scope of my field and the basic frame work of celular companies. And also it provided me the chance of learning with the most expierenced person of the company so overall it was a good learning expierence. Recommendation:- -> At sites the technicians and engineer safety must be the priority of PTCL because at many sites like DHA phase-1 and many other sites the tower is just at the edge of building at 4 th or 5 th floor. -> PTCL must increase the number of his workers because only 2 engineers and 6 technicians are dealing with north and south regions so there is a lot work load on technitions. -> PTCL must offer paid internship for students who are doing 6 weeks internship as PTCL is paying internees who are doing 1 year intrenship. 10. References:- The references from where i took help to prepare this report. -> http://en.wikipedia.org/wiki/Pakistan_Telecommunication_Company_Ltd ->http://www.google.com.pk/url? sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCoQFjAA&url=http%3A%2F %2Fvulms.vu.edu.pk%2FCourses%2FMCMI619%2FDownloads%2FMCMI619- Internship%2520Report %2520Format.doc&ei=9jgXUtrqNYLRhAel24CQDw&usg=AFQjCNF2zf6oMnmWWvC IrKu49pOfXNTLYw&sig2=-ysLfVlnG3Sm40KjMwPbkQ