1. Prepared by: Mohamed kamal
Mob: 00966532863494 / 00919567783559
e-mail: abdulkamalmohamed@gmail.com
ae.linkedin.com/in/abdulkamalmohamed/
Recommendations for efficient IBS DAS
Networks
2. Contents
1. Planned Sites Traffic estimation.
2. DAS solution selection (active /passive).
3. Design competence to Future technologies and needed precautions.
4. Reliability of soft tool Prediction and possible substitutions.
5. Indoor and Outdoor pre-optimization with soft tools and coverage
assurance.
6. Multi operator sharing site’s acceptance and upgrade possibilities.
7. VVIP site design requirements.
8. Upgrade requirement of old IBS with respect advanced technologies.
9. Planning –designing-optimizaion mutual coordination for new sites.
10. Standardizing design folders for acceptance among the suppliers.
3. 1. Planned Sites Traffic estimation.
• The acceptance of IBS site design should based on two main design concerns,
which are Site capacity design and Site coverage design.
• Normally the coverage design is perfectly checked by relating with the submitted
soft tool generated Prediction plots for all technology. (Challenges, see slide 8)
• Most of the current capacity designs are relayed on 2G calculations only since
the 3G and 4G calculations seems to be difficult.
• This creates bad KPIs performance in Mega IBS projects eg:- big malls, stadiums
and universities.
• The site’s capacity requirement should be determined for all technology
according to the expected number of users.
• This need high level planning by expert designers and preferred solution need to
be delivered to the DAS design supplier in advance.
4. 2. DAS solution selection (active /passive).
• The best basic solution should be Passive as it is Coverage and
Capacity balanced solution.
• High traffic prone sites will be with high calls and data usage;
coverage area must be defined to accommodate only planned
number of users otherwise Kpi will degrade because of
loading(Small cells/ hotspots/ wifi-offloading techniques are also
preferred to manage the high traffic).
• Coverage expansion in high traffic sites( with out considering the
number of users) by active sites creates bad KPIs performance in
Mega IBS projects- including big malls, stadiums and universities.
• Selection DAS in-building solution should need high care as it is
controlling CAPEX and OPEX.
5. 2. DAS solution selection (active /passive).
• Active sites are not advisable in terms of CAPEX and OPEX(Special
monitoring systems are required to know the working status and
parts gets easily damaged) Unless coverage duplication(expansion)
needed like in airport(Limited users but vast area) or small
buildings(with limited users inside) in a campus, where individual
passive sites will result in high CAPEX investments.
• Operators need to avoid promoting of the unscientific acceptance
of ACIVE sites designs. Even in towers and small buildings, the
active solution is selected with out looking different possibilities in
Passive solutions which are available with vendors and are able to
substitute the active systems.
• The selection of IBS type should be according to building type and
traffic capacity requirements of site.
6. 2. DAS solution selection (active /passive).
• Both Active and Passive sites need a source for all technologies. But only Passive
site efficiently utilize the 100% of RF source power. The Active unit utilize a small
fraction of RF source power(Remaining wastage) but it could repeat and serve at
remote location; it never duplicate or increase the capacity of system(helps to
grab higher order modulation by delivering extended/good coverage).
• So any addition of Capacity by means of additional sectors or telecom site, will
contribute wastage of RF source power. Where in Passive sites, addition of
capacity will allow expansion of coverage.
• Since Active solution could serve large area it could accommodate more users
and could create loading in all technologies if the designed capacity is less and
creates bad KPI performance and customer dissatisfaction.
Site with s/m Power output
X (Normally DAS Input),
available traffic capacity Y
and area of serving Z units.
Passive IBS Site dimensioning
“X+Y+Z”
Active/Hybrid IBS Site dimensioning
“X+Y+nZ”
Site with s/m Power output X (Active Master unit
requires only 3 or less percentage of X as input), available
traffic capacity Y and area of serving can be multiplied
(nZ) units when compare with passive.
7. 3. Design competence to Future technologies and needed
precautions.
• The below points must be considered while approving a
design.
For Active and Passive solution
1. Compatibility of components to upcoming technology and frequency band
(eg:-2600MHz).
2. Quality of used components(Untested Cheap Chinese components can
introduce PIM while we use higher order modulations- PIM testing advisable
after implementation).
3. Design should consider current latest technology as a base reference; The
current designs should consider LTE reference signal as the power reference,
so the designs could accommodate previous technologies and future
technologies.
4. Active system’s supporting bands and technologies must be verified.
8. 4. Reliability of soft tool Prediction and possible substitutions.
• Blindly believing the soft tool prediction could create bad KPI performance after
Implementation.
• Soft tool prediction could be fake in below cases.
• The auto cad line(Walls) will be having multiple superimposed lines while
importing to tools like iBwave, this could cause wrong wall loses resulting wrong
prediction.
• Even the wall height could be lover than prediction level and will give wrong
result.
In such cases, since the
prediction level is not meeting
the walls and will not consider
the wall losses while
calculation. Additionally,
iBwave defined wall loss also
need to be checked while
acceptance.
9. 4. Reliability of soft tool Prediction and possible substitutions.
• To avoid this we could use cw transmitter for coverage propagation
testing at individual sites.
• The coverage gaps after implementation is because, we are only
considering the coverage predictions from iBwave or other
simulation tools only
10. 5. Indoor and Outdoor pre-optimization with soft tools and
coverage assurance.
• iBwave is a strong tool with which we can input the pre-walktest
logs of a site and could identify issues with respect to the designed
site’s planned Rf conditions.
• This will help us to deliver an optimum design.
11. 6. Multi operator sharing site’s acceptance and upgrade
possibilities.
• Sharing site acceptance should make sure the future carrier
upgrade and technology upgrade possibilities in active sites for all
operator.
• All new designs, where currently other operators are not
approached the Building management for new DAS, should be
designed as multi operator Sharing DAS as an advanced step for
sharing (Normally, Site acquisition team do special contract with
building management in such cases).
• Site sharing with other operator should meet all operators’s design
criteria.
12. 7. VVIP site design requirements..
• VVIP sites Designs must be prioritized for passive solution.
• This will reduce the maintenance and optimization requirements
and could reduce frequent access to site.
• All kind of monitoring for passive sites are easy when compare with
Active solution.
13. 8. Upgrade requirement of old IBS with respect advanced
technologies.
• The existing IBS sites need to be reviewed with respect to the
advancement in technology; to enhance customer satisfaction and
business development.
• Bandwidth compatibility of DAS components, low EIRP at antenna
end, Base station upgrade requirements will be the challenges and
this could be overcome by proper review of designs from operator
end.
14. 9. Planning –designing-optimizaion mutual coordination for new
sites.
• All new Site’s frequency and capacity Planning should be done care
fully.
• Unscientifically planned sites need to be planned well for better
performance.
• For big campus’, even we could see the planned site sectorization
are implemented wrongly, proper verification of as built should be
conducted by operator.
15. 10. Standardizing design folders for acceptance among the suppliers.
• It is mandatory for an organization to have a standardized criteria
for accepting the suppliers outcomes
• There should be a standardized design folder format for design
acceptance for all suppliers.
• Which will unify the task and ease the acceptance from operator
end, and will reduce the malpractices in design by the supplier.
