The database tracks subscribing accounts, cable services subscribed, channel line-up, and pricing. The following detailed information requirements need to be represented by ERD. 

Database should store information about each current or past subscriber, such as first name, last name, subscribing address, billing address, and phone number. Each subscriber is assigned a unique account Id. A current subscriber is one who currently has cable services installed. A past subscriber is one who once had cable but now has disconnected. Installation date and disconnection date, if disconnected, should also be stored in the database. When a subscriber disconnects and later reinstalls, he'll be given a new account id. When a subscriber moves to a new address, he'll also be given a new account Id.

Cable market is divided into different submarkets (e.g. East, West, North, South, and Central). The submarket divisions are exclusive, that is, a subscription address can only belong to one submarket. Each submarket has a unique name.

The cable company offers 3 levels of services to all customers in all submarkets: basic, standard, and premium. The Basic service contains a group of about 10 channels; the Standard, about 25 channels; and the Premium, about 60 channels. The Standard consists of all channels offered at the Basic level, plus some more. The Premium consists of all channels offered at the Standard level, plus some more. The channel packaging is the same across all submarkets and all accounts. The database needs to store information about how channels are packaged. This information may change from time to time. However, only the current packaging is stored.

Information about channels include unique channel name (e.g. A&E), current channel line up number (e.g. 41), and offering company name (e.g. AETN). The channel line-up is the same across all submarkets and all accounts. The channel line-up may change from time to time. However, only the current lineup is stored. (Notice the difference between "channel name" and "channel line up number." When we say "Channel 41 is A&E," we mean "A&E programming is sent through the band of frequencies denoted by the number 41.")

Monthly subscription fee for a particular level of service (say, the Basic) is the same across all markets. Of course, higher level of services cost more than lower levels.

A subscriber account can only subscribe to one level of service. 

The database should record information about channels, channel line up, service packaging, service pricing, and subscription levels, as described above.