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Exclusive to African Cellular!
Whats Inside an IDEN Digital Phone
Q: What is
Tantalum?
A: Its what makes
your phone so smal!...CLICK HERE!
SINGLE BOARD DUAL-BAND HANDSET REFERENCE DESIGN FOR GSM900 &
GSM1800 (using the
Mobilink MTI-1400 reference design as an example)
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User
Interface
· Foreign language fonts, incl. Chinese
· Flexible Phone book
- Store numbers in phone (ME)
- SIM Abbreviated Number Phone Book
- SIM Fixed Number Dialing
· Stores last 10 numbers called & received
· Generate DTMF tones during call
· Speaker/sidetone/mic amplification control
· Visual indication of remaining battery life
· Integrated data and fax adapters
Software & Services
· Full Rate/Enhanced Full Rate Speech with DTX
· Short Message Services (SMS)
· A5/1 and A5/2 encryption
· Group 3 fax & Ph. 2 Supplemental services
· GSM data service
-Full rate 9.6, 4.8, 2.4 Kbps
-Half rate 4.8, 2.4 Kbps
· Hardware support for Phase 2+ data service:
-14.4 Kbps data service
· Layers 2/3 & MMI software supplied
-Type Approved GSM Phase 2 protocol stack
The
MTI-1400 Reference Design is a breakthrough in design
compactness, performance and quantity of features. This
single-board design shows Mobilink's capability to provide the
total solution for low-power GSM multi-band handset
applications. By using the circuitry and software employed by
the MTI-1400 design, customers can quickly and easily create a
unique product to their own specifications.
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The
Mobilink MTI-1400 Reference Design
above is a dual-band GSM handset on a single PCB.
This solution demonstrates how a Mobilink ML2000-family chip
can be used to create dramatically smaller dual-band handsets,
at lower costs than current multi-board solutions.
The single-board design greatly simplifies the manufacturing
processes and enhances product reliability.
Voice
quality can be either Full Rate or Enhanced Full Rate. Higher
rate wireless e-mail and data transfers are possible via Phase
2+ 14.4 Kbps data service.
The long
talk and standby times of the MTI-1400 Handset Reference Design
results from the use of a low, 2.8V supply voltage and
intelligent power management, including power-down scheduling
for on-chip functions and external components during inactive
intervals. The very long standby time is achieved via smart
microprocessor scheduling and power-efficient sleep-mode design.
To
accelerate our customer's product development cycle, we also
offer total system solutions including the evaluation board,
complete system software, and extensive hardware and software
support through Full Type Approval (FTA).
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Designed
to ensure low-cost production goals, Mobilink employs a
six-layer and five-mil PCB design rule process. The drill hole
diameter is no smaller than 10mil to avoid the extra cost of
optical drilling. Blind-via technology is applied instead of
expensive micro-via design. The result is approximately 1200mm2
of baseband circuit area and 2800mm2 of RF circuit area.
All
baseband and RF circuitry fits onto a single board. Since it is
a single board design, manufacturing costs are reduced relative
to conventional multi-board designs. Connectors exist for the
LCD panel, SIM card, battery charger, antenna and system
accessories and one side of the board has keypad patterns.
Software
components for the LCD and keypad are easily altered for
specific changes and the memory system can be changed from the
128K x 8 SRAM and 512K x 16 FLASH provided. The flexible
architecture of the baseband codec hardware allows customers to
choose from a wide variety of microphones and speakers.
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Starting
with this compact design, Mobilink's engineering teams work with
customers in BOM optimization, and feature and form factor
customization, in order to match every detail of the
requirements. Mobilink's in-house expertise allows customers to
add or alter software and mechanical features or hardware
interfaces, and quickly get a product design through Type
Approval and field trials. This industry-leading design
demonstrates Mobilink's commitment to low-cost, low-power,
high-performance RF design.
For
more information, please contact:
e-mail:
info@mobilinktel.com
web: www.mobilinktel.com |
Select an area inside this demo cellphone design:
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Component |
Purpose |
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Microphone |
Captures your voice for
conversion from analogue to digital mode |
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Speaker |
Allows monitoring of remote
phone |
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LCD Display |
Shows Call, Phone, Signal &
Network Info |
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Keypad |
Allows access to specific remote
phones |
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Battery + Meter |
While battery housings on
cellphones are standard input deigns, some cellphones also have
some "battery processing" intelligence built in. For example,
they will check the charge level to start or stop the charge
when the phone is connected to a desktop, car or quick charger
and even automatically discharge the battery for you when
necessary. This is usually linked to the LCD display and to an
audible beep to warn you of the battery charge status. |
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LED Lights |
Status Information, usually
Green, white & Red. |
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Digital Signal Processor |
The DSP chipset is a critical
component. It co-ordinates the voice, SMS and data/fax features
of a cellphone. It processes speech, handles voice activity
detection, as well as discontinuous GSM transmission and
reception. Another section amplifies the input signal received
from the microphone, while another converts this microphone
voice signal from "analogue" to "digital". The digital
conversion is necessary because the GSM cellular standard is a
completely digital system. |
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CODEC |
This DSP's voice processing is
done in tandem with highly sophisticated compression technique
mediated by the "CODEC" (compressor/decompressor) portion of the
cellphone. T |
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RF Unit |
The CODEC chipset instantly
transfers this "compressed" information to the cellphone’s Radio
Frequency (RF) unit. This RF unit, which is essentially the
transmit and receive section of the cellphone, then sends out
the voice or data information via the cellphone antenna, over
the air and on to the nearest cellular base station - and
ultimately to your call destination.
The incoming voice also travels much the same route, although it
is first uncompressed from it’s incoming digital form into an
audible analogue form which is then piped out as sound through
the cellphone’s speaker. This analogue-to-digital and
digital-to-analogue voice conversion via the CODEC is done at
very high speeds, so that you never really experience any delay
between talking and the other person hearing you (and visa
versa). |
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SIM Card Reader |
When you switch on your phone
with a "live" SIM card inside, the subscriber information on the
chip inside the SIM card is read by the SIM card reader and then
transmitted digitally to the network via the RF unit. The same
route is followed when you hit the Call button (and it’s
variants) on the cellphone: the number you’ve inputted is
instantly and digitally transferred to the network for
processing. |
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External Connectors |
At the bottom of most cellphones
there is an external connector system. You can usually plug in a
data/fax adapter, or a battery charger, or a personal hands free
device, or a car-kit with external antenna connections. You’ll
also find many with separate "speaker" and LED lights that are
activated when the phone rings and/or when the battery is low.
Many phones also have tiny LED lights under the keypad that
light up when you press a key and/or when the phone rings. |
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On-Board Memory |
Many cellphones also have a
certain amount of on-board memory chip capacity available for
storing outgoing telephone numbers, your own telephone number,
as well as incoming and outgoing SMS messages. Some allow
copying between the (limited) memory on the SIM card and the
phone’s own internal memory. |
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Antenna System |
Cellphone manufacturers are
implementing many weird and wonderful permutations of antenna
system designs. While some are stubby, fixed types, the most
predominant designs though are those with thin, pull-out steel
rods all of whom usually fit snugly into a special antenna
shaft. These antenna designs, be they the stubby or pull-out
types, all conform to the same circa 900 MHz frequency transmit
and receive range required by the GSM specification. |
Disclaimer!!
The above is a merely a very rough, schematic
interpretation of what is inside a GSM cellphone.
The components will vary from cellphone model/brand/design to cellphone
model/brand/design.
We will not be held liable for use or misuse of this data.
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