Network Planning and Design
Diversity of network elements and hierarchies,
diversity of services and options for carrying them, diversity of
embedded bases, and multiple business imperatives make the network
planning and design function interesting and challenging.
Decisions on technologies, interconnections of various technologies
and protocols, relationships between service mix and networking
technologies, topologies, and introduction timing play the major
role in network planning function.
Given a composite traffic, and its spatial and temporal
characteristics, the big challenges in network planning and design
are dealing with the network topology design, identifying the
network architecture, and the key characteristics of network
elements in terms of both their key capabilities/constraints and the
A number of chief issues involved in network planning are:
- Traffic planning
- Topology planning
- Technology planning
- Characterizing networking technologies
(their capabilities, cost structure, etc)
- Capacity planning
- Near-term deployment phase
- Medium-term deployment phase
- Long-term deployment phase
The objective of network design is to minimize the
overall network cost while meeting customers’ network performance
objectives. The design should specify the selection of topology
(location of major access, service and transport nodes and
interconnections among them), the network architectures, the key
characteristics of network elements in terms of their both
capabilities/constraints and cost structure, routing strategies, and
A good network design is of immense value to Network and Service
Providers since they are interested in obtaining the lowest-business
cost network designs to keep their operating expenditures (OPEX) and
capital cost (CAPEX) as low as possible. Network design helps in
this regard by optimizing the access and transport cost. It is the
transport cost, which is a significant recurring part of the cost of
providing access services.
A versatile network design which can accommodate multiple interface
technologies, multiple infrastructure technologies, and multiple
tariff structures (domestic and foreign) will be of great value for
the Network Providers and Operators.
There are two main categories of network design
- green field design (for new entrant on
- growth design.
Designing a new network from ground zero is
considered a green field design. Adding capacities to accommodate
growth on an existing network design is design for growth. The need
for network growth occurs in response to a number of different
causes, such as geographic movement of end users, an increase in the
number of end-users or an increased bandwidth requirement.
Telecom Network Providers design mainly an optical fiber or radio based
infrastructure. The infrastructure consists of three
components. The first component is the access network. The second
component of infrastructure includes service nodes providing various
circuit-, packet–, and cell-based services using switches,
cross-connects, routers, gateways, and so on. The third is the
core/backbone transport network. It includes SDH, WDM, and so on.
So, at a high level, the design of Telecom Network consists of
three components: an access network design (AND), a service layer
mesh network design (SND), and a physical layer ring or mesh network
Here, first we state the (long-term) network
design principles and define a set of generic network elements.
Next, we present a systematic approach for the design of Telecom
Network and proceed with the functional design procedure for AND,
SND, and PND.