2.5G or 3G Migration RF Design Procedure

The process for introducing a 2.5G or 3G platform into an existing wireless
system needs to account for the impact the reallocation of the spectrum will
have on the legacy system. Also, the design needs to address the new platforms
and the modifications to the existing platforms, which are needed to
facilitate the introduction of the new system. Therefore, the following is a
brief summary of the main issues that need to be addressed when integrating
a new platform into an existing system:
1. Obtain a marketing plan.
2. Establish a technology platform introduction time table.
3. Determine new technology implementation tradeoffs.
4. Determine a new technology implementation methodology (footprint
and 1:1 or 1:N).
5. Identify coverage problem areas.
6. Determine the maximum radius per cell (link budget for each
technology platform).
7. Establish environmental corrections.
8. Determine the desired signal level (for each technology platform).
9. Establish the maximum number of cells to cover an area(s).
10. Generate the coverage propagation plot for the system and the areas,
showing before and after coverage.
11. Determine the subscriber usage (existing and new; packet and voice).
12. Determine the subscriber usage by platform type.
13. Allocate the percentage of system usage to each cell.
14. Adjust the cells’ maximum capacity by spectrum reallocation method (if
applicable).
15. Determine the maximum number of cells for capacity (technologydependent).
16. Establish which cells need capacity relief.
17. Determine the new cells needed for capacity relief.
18. Establish the total number of cells required for coverage and capacity.
19. Generate the coverage plot, incorporating the coverage and capacity
cell sites (if different).
20. Re-evaluate the results and make assumption corrections.
21. Determine the revised (if applicable) number of cells required for
coverage and capacity.
22. Check the number of sites against the budget objective; if it exceeds the
number of sites, reevaluate the design.
23. Using the known database of sites, overlay on the system design and
check the matches or close matches (
0.2R).
24. Adjust the system design using site-specific parameters from known
database matches.
25. Generate the propagation and usage plots for the system design.
26. Evaluate the design objective with time frame and budgetary
constraints and readjust if necessary.
27. Issue search rings.
The previous two procedures can be easily crafted into a checklist to follow
for the design team. Obviously, the lists are generic and need to be tailored
to the specific situation. However, when using the lists, whether it is for
a new system or the migration from 2G to 2.5G or 3G, it should provide sufficient
guidance in order to organize the process for a successful design that
will meet the customer and business objectives for the wireless company.