Network Maintenance

SIMS

Understanding Cell site Infrastructure

A cell site is a cellular telephone site where antennas and electronic communications equipment are placed, usually on a radio mast, tower or other high place, to create a cell (or adjacent cells) in a cellular network. The elevated structure typically supports antennas, and one or more sets of transmitter/receivers transceivers, digital signal processors.A cell site is sometimes called a "cell tower", even if the cell site antennas are mounted on a building rather than a tower. In GSM networks, the technically correct term is Base Transceiver Station (BTS), and colloquial British English synonyms are "mobile phone mast" or "base station". The term "base station site" might better reflect the increasing co-location of multiple mobile operators, and therefore multiple base stations, at a single site. Depending on an operator's technology, even a site hosting just a single mobile operator may house multiple base stations, each to serve a different air interface technology (CDMA2000 or GSM, for example).Telecom InfrastructureBasically a cell site consists of electronic (active) and non-electronic infrastructure.

•Electronic infrastructure includes base tower station, microwave radio equipment, switches, antennas, transceivers for signal processing and transmission.•Non-electronic infrastructure includes tower, shelter, air-conditioning equipment, diesel electric generator, battery, electrical supply, technical premises and easements & pylons that account for nearly 60 percent of network rollout costs

Module1 Intro to SIMS

2

3

4

Routine Maintenance

Generator Maintenance

Fault Resolution & Other Terms

1 Intro to SIMS

Site Integrated Maintenance

SIMS – Site integrated Maintenance Services

Passive-

Routine and Non Routine

Active- Link

Maintenance

SIMS

Intro to SIMsPassive Maintenance comprises of:

• Routine Maintenance

• Non Routine Maintenance

Intro to SIMsRoutine Maintenance comprises of the following task:

DC Power maintenanceDiesel Delivery and ManagementSecurity Services Mechanical Maintenance which include Fence, Shelter and AC maintenanceTower member maintenanceJanitorial Cleaning

Above are undertaken monthly expect tower and mechanical maintenance which are quarterly

Non routine maintenance takes charge of sudden fault repairs(Minor/Major) such as complete/partial overhauling(Knocked Engine), fan belt replacement, PHCN Infrastructures and other services not captured in the SOW. Necessary approval must be sought before implementation.

2 Routine Maintenance

Routine MaintenanceRoutine Maintenance includes activities that need to be carried out on a regular basis on intervals as defined in the MTN Contract. The regular maintenances are contractual obligations aiming at prolonging the life expectancy of the MTN equipments/assets through preventive actions and early detections of problematic issues.

Well planned and systematic execution of Routine Maintenance has also direct impact on the quality of deliverables. They allow reduction and better management of unexpected events. Thereby, reduces the strain and stress imposed on the team and avoid the fire fighting scenario.

TERMS

MTTR - Mean Time To Resolve( 2hrs)MTBF - Mean Time Before Breakdown

NB MTBF> MTTR = Zero down time

Routine MaintenanceSLA FOR MTN ROUTINE MAINTENANCE

MAIN DELIVERABLES TASK WKLY

Every 2 WKS Mthly 1/4ly Yrly 250 Hrs 1000 Hrs 2400Hrs

Tower

Tower       X X      Foundation       X X      Obstruction Lighting       X X      Earthing System       X X      Locking Devices         X      Vertical Alignment         X      

Mechanical

Fence     X          Equipment Housing     X          Air Conditioning Unit     X          

Site SecurityAssessment       X        Recommendation       X        

DC MaintenanceRectifier     X          Battery     X          UPS     X          

Utility

PHCN Connection     X          PHCN Status & Quality     X          PHCN Related Problem     X          

Generator

Generator Running   X       X X  ATS           X    AVR           X    Diesel Level Verification X              

JanitorFumigation       X        General site cleaning     X          

3 Generator Maintenance & Other Services

Generator MaintenanceGenerators are serviced depending on the Run Hour, brand, capacity and model as stated below:

ASSUMPTION

S

SITE WITH PHCN   SITE WITHOUT PHCNGEN TYPE : 1000RH GEN TYPE : 250RH   GEN TYPE : 1000RH GEN TYPE : 250RH

MONTHLY

SERVICING FREQ

in DAYS

MATERIALS  

MONTHLY

SERVICING FREQ

MATERIALS

Oil Filter

Fuel Filter

Engine Oil

MONTHLY SERVICING FREQ

Oil Filter - 1pc/Serv

Fuel Filter

Engine Oil  

Oil Filter

Fuel Filter

Engine Oil

MONTHLY SERVICING FREQ

Oil Filter - 1pc/Serv

Fuel Filter

Engine Oil - 8ltrs/Serv = 25ltrs

BEST CASE : PHCN AVAILABILTY - 12hrs. GEN - 12hrs

83

1 1 55ltrs

21 1 1

8 ltrs

 

42

1 1 55ltrs 10.416667 3 3 25

ltrs

AVE CASE : PHCN AVAILABILTY - 6hrs. GEN - 18hrs

56

14 2 2  

WORST CASE : PHCN AVAILABILTY - 3hrs. GEN - 21hrs

48

12 3 3  

HYBRID : AVAILABILTY - 8hrs. GEN - 16hrs

63

16 2 2  

Other ServicesDiesel Delivery – This is a function of generator age, load and site capacity as volume and consumption are dependent on above variables

15kva BTS site without PHCN – 1850 ltrs27kva Backbone site without PHCN – 2400ltrs15kva BTS site with PHCN – 1100ltrs

After every diesel delivery , it is important to record the generator RH as this helps to determine generator daily consumption.

Timely and accurate diesel delivery help reduce DOWNTIME to the minimal as this(Diesel) represent the hub of MS.

4 Fault Resolution & Other Terms

Fault ResolutionAll fault are expected to be cleared within the allowable time limit – 2hrs, failure reduces SMC’s availability(98%) measured in percentage. Else penalty of 113,500/ hour starts counting.

Mobile gen must be deployed to rescue site during major fault that cannot be resolved within 2hrs to avoid penalty charges.

Ref must provided by MTN NMC before site access

Battery back must be in top gear to avoid unnecessary down time

All alarm system must be wired and functional

All opened ticket must be closed via necessary feedback from field engr. to MTN NMC/NOC.

Other TermsMean time between failures (MTBF) : is the predicted elapsed time between inherent failures of a system during operation. MTBF can be calculated as the arithmetic mean (average) time between failures of a system. Mean Time To Repair (MTTR) : is the time needed to repair a failed hardware module.Availability: Availability of the module is the percentage of time when system is operational. Availability of a hardware/software module can be obtained by the formula given below. A = MTBF/ MTBF+ MTTR

Failures : Total period an equipment was unable to achieved its main objectives.Remedy : Place where fault log are stored/ Kept for future reference