Cellular Essay (ameritech) Essay, Research Paper

The orange is the home digital service

area and the yellow is analog service area. Ameritech also offers

free long distance all over the U.S.A. With a special package deal

they have going right now. For sixty-five dollars a month you get

325 minutes per month. For their Chicago land service area it depends

on which plan you pick, because the local rate per minute could either

be .25 cents or .29 cents per minute for local calls that went over your

minutes you received for free already. The price per minute also

changes depending on if you are in the peak or off peak time slots.

Peak hours are from 6 a.m. to 10 p.m. Monday through Friday. Off

peak times are from 10:01 p.m. to 5:59 a.m. Monday through Friday.

Saturday and Sunday are all day off peak and some holidays. Long

distance runs from .25 cents per minute to .35 cents per minute.

Depending on the distance it varies. If you leave your service area

and enter another then roaming charges will be also added. If you

decide to go with a cellular phone they have package deals that include

a cell phone for a thirty five-dollar activation fee. They offer

several packages to meet everyone?s needs. You may also upgrade to

a better phone, but then you must purchase that phone.

I contacted Ameritech and they told

me that because I wasn?t a business that they were unable to release that

information. They then told me that they would get a hold of one

of their managers and maybe they could give me this information.

They took my name and number and I never received anymore information.

I told them this was for a school project, but that didn?t matter.

The PBX I chose was Meridian1 option

11c. This is a powerful PBX that comes in a small package.

It supports 30 to 400 lines. Some other features are digital telephones,

in building wireless communications, voice messaging, call center, PC-based

system management, Ethernet connection, remote connection, keycode software

activation, and multimedia applications. This PBX can be easily upgraded

to new capabilities. Some of the programs that this PBX can run are

Computer Telephony Integration (CTI), Customer Controlled Routing (CCR),

and Integrated Voice Response (IVR).

Dual-tone multifrequency dial (DTMF)

is a keypad containing 12 to 16 buttons. These are arranged in columns

and rows. When the buttons are pushed they send two tones to the

central exchange. The central exchange decodes the tones and rings

the destination. A rotary phone or pulse dialing phone is sent over

by clicks. The rotary dial contains two separate contacts.

These contacts open and close for every digit. So if the number 3

were dialed, then the contacts would open and close 3 times. But

a pulse dial will not pass through the central exchange. Which means

that if a voice mail system answers you can not get through to the menu

options. The number 8 tones are column 1336 Hz and row 852 Hz.

For the central office to receive the tone it must be present for 40 ms

and a pause of 60 ms between digits. For a rotary phone it takes

15 seconds to transmit 10 digits.

Carried Load: calls that are served, traffic

that is carried to its destination

Offered load: arriving calls, calls attempting

to enter a system

Blocked calls: traffic that can not be

carried to its destination, blocked calls leave the system or overflow

to another circuit

Blocked Calls-Cleared: upon receiving indication

that all circuit are busy and can not be handled, the caller hangs up and

is lost to the system.

Blocked Calls-Delayed: upon receiving indication

that all circuits are busy, the caller waits and is held in the system

until it can be processed.

First attempt traffic is a formula that

Jacobsen developed to figure the percentage of people who retry their call

immediately.

The Jacobsen retrial table assumes

that 70% of the people retry immediately. Henry Jacobsen developed

all of the retry tables. These tables help the server?s figure out

how many blocked calls that they receive. This allows them to figure

if they need more lines or how many lines they will need in a certain area.

PCS: Personal communication service, transmit

1850-1910 MHz, receive 1930-1990 MHz

PCS 1900: Provided by time division multiple

access or code division multiple access technology.

BSC: Connects to base transceiver station

sites.

BTS: Base transceiver station for the PCS

1900 is a building that holds base station transmitter and receivers and

antenna tower. The tower has 9 antennas with one transmitting antenna

and two receiving antennas?.

HLR: Home location register tracks if the

phone is in the home service area

BTA: The 51 trading areas were divided

into basic trading areas

MTS: Mobile telephone system that uses

35 and 45 MHz radio frequencies

The personal communication service (PCS)

transmits 1850-1910 MHz and receives 1930-1990 MHz. It uses pulse

code modulation and uses 256 levels. Which is full duplex.

Mobile telephone service used 35-45 MHz.

This was mostly two-way radio?s. MTS is a half-duplex system.

Cellular Radio transmits 825-845 MHz and

receives at 870-890 MHz. Cellular radio is analog. It is also

full duplex.

Multiplexing: The process of combining

many individual signals so they can be sent over one medium.

Time Division Multiplexing: Converting

speech paths into samples, then combining the different samples by transmitting

each sample at a different time, so it can be transmitted over one medium.

Space Division Multiplexing: Multiple communications

are placed over different wire pairs inside one cable.

Frequency Division Multiplexing: Converting

each speech path to different frequency signals and the combining the different

frequencies so they are sent over one medium.

RS232

Automatic call distributor uses DTMF digits

to handle calls. It might process calls by automated features like

telling you to press one to go to a certain area of a company.

Uniform call distributor is a feature that

is on most PBX?s. This connects the calls in sequential fashion.

The first agent gets the most calls and the last agent gets the fewest.

A call sequencer is the least sophisticated

call distributor. It leaves it up to the agent to decide which call

to answer.

The Nyquist theorem is the samples

rate of an analog signal twice its highest frequency. If the highest

frequency were 4000 Hz then 8000 would be twice of the 4000. So you

would take a sample every 1/8000 of second.

A key system is a special telephone

that can handle access to several different telephone lines. A key

system would be good for a business that had to answer telephones by an

operator in order. Like they used a key system at Pizza Hut that

I use to work for. The phones could handle several lines that a person

would answer to take someone?s order.