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.