Local Number Portability Traffic Analysis Calculations ENGR 475 – Telecommunications October 19, 2006 Harding University Jonathan White

Outline - LNP  Definition of Local Number Portability Required by Law Required by Law  New components in the network  Why have LNP  Wireless and LNP  911 and LNP

Outline – Traffic Analysis  What Traffic Engineering is used for  Busy Hour traffic  A.K. Erlang’s Distributions  Examples of board

Local Number Portability  LNP – Mandated by the Telecommunications Act of Mandated by the Telecommunications Act of Telcos had until 2002 to completely comply. Telcos had until 2002 to completely comply.  What it is: Consumers can keep their telephone number and have any provider that will serve them. Consumers can keep their telephone number and have any provider that will serve them. Consumers can also keep their telephone number when they move to a new location. Consumers can also keep their telephone number when they move to a new location.

Benefits of LNP  More competition drives lower prices and better service. Telecommunications biggest enemies: Telecommunications biggest enemies: ChurnChurn FraudFraud  Most people want to keep their telephone numbers. Why would this be true? Why would this be true?  The LNP act gives these people the ability to have competition for their dollars.

Wireless LNP  Because of LNP, you can get a local telephone number any where in the US, no matter where you live. For example, I bought my phone in Bentonville, Arkansas, but I was able to get a local Searcy number. For example, I bought my phone in Bentonville, Arkansas, but I was able to get a local Searcy number.  However, having wireless LNP makes billing even more complex.

Additional Network Objects  On the SS7 network, a new database is required to support LNP so that the call is routed across the correct network. Providers can actually pay to have access to updated LNP databases. Providers can actually pay to have access to updated LNP databases. GTE and Cincinnati Bell Information ServicesGTE and Cincinnati Bell Information Services  This adds cost and delay to the system.  This database is called the local service management system. Local SMS. Local SMS.

911 and LNP  The 911 system used to derive location information based on your telephone number. No longer directly possible. No longer directly possible.  Your location information is now passed to 911 through database access.  This makes the 911 system less reliable.

911 and Wireless  Cell phone towers are no equipped with GPS units so that they can calculate where your call came from. If 3 or more towers are within your signal range, they can triangulate your exact location. If 3 or more towers are within your signal range, they can triangulate your exact location.  But again, LNP means 1 more database dip. Also, the databases must be maintained. Also, the databases must be maintained.

Who Pays  We ultimately pay for local number portability.  Is it worth it?

Traffic Analysis  Method for determining the cost effectiveness of various sizes and configurations of networks.  Helps us to decide how many telephone trunks we should use to service organizations.  Formulas were used; now, computer modeling is almost exclusively used.

Uses of Traffic Engineering  Utilizing the correct number of links at the best price point. Cost versus effectiveness Cost versus effectiveness  What do you engineer to? The busiest hour? The busiest hour? The average amount of traffic? The average amount of traffic? The minimum required that will still retain customers? The minimum required that will still retain customers?  How are our road systems engineered?

Agner Krarup Erlang  Danish mathematician and engineer – – 1929  Worked for the telephone company in Copenhagen from 1908 to  Applied math to calculating how many circuits and telephone operators were needed.  His formulas were incredibly good for the time period, and they were used until very recently.

Grade of Service  GOS – How many callers will be refused service. This could be a busy tone or a redirection to voice mail. This could be a busy tone or a redirection to voice mail.  Telephone companies have designed their networks so that the probability that a circuit will be blocked must be between 1 and 5 percent. To get a lower blocking percentage than 1 percent gets exponentially more difficult. To get a lower blocking percentage than 1 percent gets exponentially more difficult.

Traffic Analysis  Erlang’s ideas are used extensively in: Data networks Data networks Voice networks Voice networks Busy hour traffic on interstates Busy hour traffic on interstates Banking/Supermarket queuing theory. Banking/Supermarket queuing theory. General max/min optimization problems General max/min optimization problems

Traffic Analysis  The rest is on the board