S-Fone

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S-Fone" the fourth largest mobile communication operator Vietnam that uses the CDMA technology. Founded on 01st July, 2003 in HCMC, Vietnam.

"S-Fone" is the brand name (trademark) of S-Telecom (CDMA Mobile Phone Center).

S-Telecom is the company founded between Saigon Postel Corporation and SLD Telecom (SK Telecom, LG Telecom & Dong Ah Telecom from Korea). The contract between them is the BBC contract.

"S-Fone" is known as the 1st mobile network in Vietnam breaking the old rule of the calls fee from 10 second to 1 second (6+1).

Moreover, S-Fone breakthough makes the others' big old network to reduce the calls fee as well as the customers careness' quality in order to prevent from losting subscribers to S-Fone. This makes the Vietnamese customers have got more benefits than they had been having during nearly 10 years with expensive calls fee of Vinafone & Mobifone.

As of the start of 2007, S-Fone has 1,500,000 to 1,800,000 subscribers.

S-Fone's always appreciated from the Vietnamese journalists and customers.

S-Fone will be leading in the telecom field in a near future.

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Video/TV on demand, music on demand, Mobile Internet have become possible via S-Fone network October 18 2006

October 9, 2006, S-Fone officially launched CDMA 2000 1x EV-DO value added services for the first time in Vietnam: VOD/MOD (Video, TV on demand, music on demand) and Mobile Internet (enabling internet access for PCs and laptops via S-Fone network)

EV-DO (Evolution-Data Optimized) is the standard for broadband data transmission on wireless devices. CDMA 2000 1x EV-DO, allowing data transmission at high speed (2.4 Mbps), enables the provision of large files. After upgrading the infrastructure system, S-Fone has officially introduced EV-DO applications to Vietnamese customers for the first time. They are VOD, MOD and Mobile Internet.

With VOD (Video-on-demand), S-Fone customers can see films or TV programs in crystal clear video and high quality sound every time and every where with their mobiles. In addition to latest and hottest films, VOD provides customers with many interesting TV channels such as HBO, AXN, V-Channel, Fashion TV, VTV3, HTV7,…Besides, VOD brings customers other utilities such as Music, Cinematography, English, Make-up programs,…Customers can use the service by downloading contents from the server to their handsets, live streaming (seeing programs being broadcast on TV) or streaming (seeing contents right on the server).

Meanwhile, with MOD (Music-on-demand), S-Fone customers can change their handsets to MP3 players. With the abundant list of currently most favorite songs, MOD allows customers to enjoy music on their handsets or download their favorite songs to set them as ring tones.

Moreover, VOD and MOD allows S-Fone customers to introduce interesting melodies, and video clips…to their beloved ones by sending links. The condition is that the receivers use VOD and MOD supporting handsets, connected to S-Fone network. VOD and MOD are provided for all S-Fone post-paid and prepaid customers.

Mobile Internet allows Internet access for PCs and laptops to the Internet via S-Fone connected handsets. Like WiFi, Mobile Internet allows customers to access the Internet everywhere within the coverage area at the speed of 2.17 Mbps, which is littler higher than that of ADSL (2 Mbps). Handsets, provided by S-Fone with compatible cables and drivers can help connect PC and laptops to the Internet.

At the beginning, these services are provided in 5 big cities: Ho Chi Minh city, Hanoi, Da Nang, Hai Phong and Can Tho.

CDMA 2000 1x EV-DO has been applied in many developed countries such as the U.S, Canada, Australia, Japan and South Korea,…Its utilities have been used in people’s daily life such as: Mobile TV, money withdrawal from ATM, payment transaction, Global Positioning System, goods purchase from Automatic Selling Machines, Mobile and Wireless Internet,…Based on this advanced technology, S-Fone has set its own way in popularizing CDMA technology’s modern services to Vietnamese customers.

On the occasion of VOD, MOD and Mobile Internet launch, Ho Hong Son, Managing Director of S-Telecom (S-Fone) said: “The 3 services introduced this time is initial step on the way of exploiting CDMA 2000 1x EV-DO’s utilities. S-Fone planned to provide more advanced utilities in the future to meet the customers’ demand for hi-tech services”

Information about service rates and guidelines are posted at website: www.sfone.com.vn

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• MORE INFORMATION:

CDMA Mobile Phone Centre works under Licence of Branch Operating Registration No. 03005683 CN 41 issued by Department of Planning and Investment of Ho Chi Minh City.

This is a cooperation project between SPT and SLD Co. (established in Singapore with founders being SK Telecom, LG Electronics, and Dong Ah Elecomm) under the form of Business Cooperation Contract to provide nationwide mobile telephony services, fixed-wireless telephony services and other value added services using CDMA 2000 – 1x technology.

CDMA mobile subscribers will benefit from many utilities of this technology such as the minimization of call interruption, high speed data transfer, the optimization of transmission power of the terminal equipments to increase talk time and latency stand-by time, at the same time be able to use many value added services such as necessary information, high speed Internet access, online gaming…

Scope of Business:

Construction of network and supply cellular mobile telecommunications service. Establishment of sales and distribution network and supply of Value Added Services initially. Setting of sales and distribution network and supply of mobile phones.

Brand name of CDMA Mobile Phone Centre:

S-Fone is the first national cellular mobile phone network using CDMA technology (Code Division Multiple Access) in Vietnam. This advanced technology, has been commercialized in the world's telecommunications market since 1995, with high packet data throughput up to 144 kbps, being many times higher than that of other cellular mobile phone networks, and nowadays has become the fastest growing wireless telephony technology in the world. The CDMA technology not only provides higher data transmission speed but also possesses globally accepted standards for the 3G Mobile Telecommunications Services that the world is longing for. The CDMA technology in fact provides customers with many benefits such as high security, ability to mininize interference enabling high voice quality and minimizing drop calls, high data transmission speed, optimized radio technology and optimization of power control for handset, hence lengthening its waiting and calling duration as well as adoption of many value added services like information, high speed internet access, game online and many more.

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CDMA MOBILE PHONE PLAN (Investment type: Business Cooperation Contract)

Ministry of Planning and Investment issued License No 2223/GP dated 12/09/2001 for Saigon Post and Telecommunication Corporation and SLD Telecom Pte. Ltd. to cooperate and do business based on regulations of Vietnam Foreign Investment Law. Objectives and scopes of the plan: Establish, exploit and develop network and provide wireless landline (WLL) mobile telecommunication services and other telecommunication services based on CDMA technology at frequency of 800 MHz in Vietnam.

The network will be updated to 3G (Third Generation) and IS-2000(IX) system.

Provide voice and value added services through mobile phone network such as: fax, data transfer, international calls, and internet access in Vietnam.

Contents: Objective: Provide service for 3,500,000 to 7,000,000 CDMA subscribers, among these will be 5,000,000 wireless landline subscribers.

Total investment capital: 229.617.000 USD includes fixed and mobile capital.

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What is CDMA? Code Division Multiple Access (CDMA) is a digital wireless technology that was pioneered and commercially developed by QUALCOMM.

CDMA works by converting speech into digital information, which is then transmitted as a radio signal over a wireless network. Using a unique code to distinguish each different call, CDMA enables many more people to share the airwaves at the same time - without static, cross-talk or interference.

Commercially introduced in 1995, CDMA quickly became one of the world's fastest-growing wireless technologies. In 1999, the International Telecommunications Union selected CDMA as the industry standard for new "third-generation" (3G) wireless systems. Many leading wireless carriers are now building or upgrading to 3G CDMA networks in order to provide more capacity for voice traffic, along with high-speed data capabilities.

Today, over 100 million consumers worldwide rely on CDMA for clear, reliable voice communications and leading-edge data services.

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The Cellular Challenge The world's first cellular networks were introduced in the early 1980s, using analogue radio transmission technologies such as AMPS (Advanced Mobile Phone System). Within a few years, cellular systems began to hit a capacity ceiling as millions of new subscribers signed up for service, demanding more and more airtime. Dropped calls and network busy signals became common in many areas.

To accommodate more traffic within a limited amount of radio spectrum, the industry developed a new set of digital wireless technologies called TDMA (Time Division Multiple Access) and GSM (Global System for Mobile). TDMA and GSM used a time-sharing protocol to provide three to four times more capacity than analogue systems. But just as TDMA was being standardized, an even better solution was found in CDMA. Commercial Development The founders of QUALCOMM realized that CDMA technology could be used in commercial cellular communications to make even better use of the radio spectrum than other technologies. They developed the key advances that made CDMA suitable for cellular, then demonstrated a working prototype and began to license the technology to telecom equipment manufacturers.

The first CDMA networks were commercially launched in 1995, and provided roughly 10 times more capacity than analogue networks - far more than TDMA or GSM. Since then, CDMA has become the fastest-growing of all wireless technologies, with over 100 million subscribers worldwide. In addition to supporting more traffic, CDMA brings many other benefits to carriers and consumers, including better voice quality, broader coverage and stronger security. Selecting a 3G Standard Just as the second generation of wireless technology improved upon earlier systems, the industry looked to a third generation of technology for more advances. Although wireless was used almost exclusively for voice communication, the ability to deliver data over the air was also very promising, especially as Internet users and content proliferated.

In 1999, the International Telecommunication Union adopted an industry standard for third-generation (3G) wireless systems that can deliver high-speed data and other new features. The 3G standard includes three operating modes based on CDMA technology, and over 50 leading manufacturers have already licensed 3G CDMA from QUALCOMM. First to 3G with CDMA2000 Because CDMA2000 is evolved directly from the previous generation of proven CDMA systems, it provides the fastest, easiest, most cost-effective path to 3G services. While all 3G technologies (CDMA2000, WCDMA and TD-SCDMA) may be viable, CDMA2000 is much further ahead in terms of product development, commercial deployment and market acceptance.

The first commercial CDMA2000 networks were launched in South Korea in early 2001, and are already providing service to over one million paying subscribers (as of September 2001), with much larger numbers expected in late 2001 and 2002. A large and growing range of CDMA2000 chipsets, handsets and network infrastructure systems are now in volume production and gaining economies of scale, as many more North American, Latin American and Japanese carriers plan to roll out CDMA2000 services in 2002. CDMA2000 builds on an installed base of over 100 million cdmaOne™ users, leveraging previous investments and industry-wide expertise in developing cdmaOne handsets. Other 3G technologies, which are radically different from previous generations, may involve very costly and complex components, new network designs and long test and deployment periods. QUALCOMM believes the proven performance and cost-effectiveness of CDMA2000 make it the best choice for 3G wireless systems. At the same time, the Company is supporting the industry with other solutions for WCDMA and multi-mode systems that will bridge the gaps between various 2G, 2.5G and 3G networks. CDMA2000 1X for Voice and Data CDMA2000 1X technology supports both voice and data services over a standard (1X) CDMA channel, and provides many performance advantages over other technologies. First, it provides up to twice the capacity of earlier CDMA systems (with even bigger gains over TDMA and GSM), helping to accommodate the continuing growth of voice services as well as new wireless Internet services. Second, it provides peak data rates of up to 153 kbps (and up to 307 kbps in the future), without sacrificing voice capacity for data capabilities.

CDMA2000 1X phones also feature longer standby times. And because it's backwards-compatible with earlier CDMA technology, CDMA2000 1X provides an easy and affordable upgrade path for both carriers and consumers. CDMA2000 1xEV-DO for Faster Data For those who want higher-speed or higher capacity data services, a data-optimized version of CDMA2000 called 1xEV-DO provides peak rates of over 2 Mbps, with an average throughput of over 700 kbps - comparable to wireline DSL services and fast enough to support even demanding applications such as streaming video and large file downloads. CDMA2000 1xEV-DO also delivers data for the lowest cost per megabyte, an increasingly important factor as wireless Internet use grows in popularity. 1xEV-DO devices will provide "always-on" packet data connections, helping to make wireless access simpler, faster and more useful than ever.

After conducting field trials, several carriers have announced plans to commercially deploy 1xEV-DO in 2002. By combining 1X and 1xEV-DO as needed, CDMA2000 provides a flexible, integrated solution that maximizes capacity and throughput for both voice and data.

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Features and Advantages of CDMA CDMA has several unique features that make it a cost-effective, high quality wireless solution. In this module you will learn what those features are and how they provide advantages

The following features are unique to CDMA technology: 

Universal frequency reuse Fast and accurate power control Rake receiver Different types of handoff 1. Frequency reuse The frequency spectrum is a limited resource. Therefore, wireless telephony, like radio, must reuse frequency assignments.

For example, two radio stations might transmit at 91.3 FM. There is no interference as long as the radio stations are far enough apart

Cell interference

Cell A and B of a conventional, analogue system are using the same frequency. The area of overlap, area C, has a frequency conflict and interference. This is similar to what you experience when you are driving between the broadcast zones of two radio stations transmitting at the same frequency. FDMA and TDMA frequency reuse planning A frequency (channel) can be used again within an FDMA or TDMA network, but cells using the same frequency must be separated by an appropriate distance.

Adjacent cells must be assigned a different set of frequencies. For example, a cell using frequency A must not be adjacent to another cell using frequency A.

As a result, each cell site in the site is able to use only 1/7 of the possible frequencies

CDMA frequency reuse planning

Each BTS in a CDMA network can use all available frequencies. Adjacent cells can transmit at the same frequency because users are separated by code channels, not frequency channels.

This feature of CDMA, called "frequency reuse of one," eliminates the need for frequency planning.

2. Power control Power control is a CDMA feature that enables mobiles to adjust the power at which they transmit. This ensures that the base station receives all signals at the appropriate power.

The CDMA network independently controls the power at which each mobile transmits.

Both forward and reverse links use power control techniques.

Why power control is needed

If all mobiles transmitted at the same power level, the base station would receive unnecessarily strong signals from mobiles nearby and extremely weak signals from mobiles that are far away. This would reduce the capacity of the system.

This problem is called the near-far problem

Reverse link power control

Reverse link power control consists of two processes:

Open loop Closed loop

Open loop is an initial estimate of the power the mobile needs to transmit to the BTS. Closed loop is a refinement of the open loop estimate.

Open loop power control

Open loop is the mobile's estimate of the power at which it should transmit. The open loop estimate is based on the strength of the pilot signal the mobile receives. As the pilot signal gets weaker or stronger, the mobile adjusts its transmission strength upwards or downwards.

Open loop is used any time the mobile transmits. Closed loop power control

In closed loop, the BTS sends a command to the mobile to increase or decrease the strength at which it is transmitting. The BTS determines this command based on the quality of the signal it receives from the mobile.

Closed loop is only used during a call. Closed loop commands are sent on the forward traffic channel. Forward link power control

The BTS independently adjusts the power for each forward traffic channel based on the information it receives from the mobile.

3. Rake Receiver The rake receiver is a CDMA feature that turns what is a problem in other technologies into an advantage for CDMA.

The multi-path problem

Signals sent over the air can take a direct path to the receiver, or they can bounce off objects and then travel to the receiver. These different paths, called multi-paths, can result in the receiver getting several versions of the same signal but at slightly different times.

Multi-paths can cause a loss of signal through cancellation in other technologies.

How the rake receiver works

CDMA's rake receiver is multiple receivers in one. The rake receiver identifies the three strongest multi-path signals and combines them to produce one very strong signal.

The rake receiver therefore uses multi-path to reduce the power the transmitter must send.

Both the mobile and the BTS use rake receivers.

4. Handoff in CDMA Handoff is the process of transferring a call from one cell to another. This is necessary to continue the call as the phone travels.

CDMA is unique in how it handles handoff.

Types of CDMA handoff

CDMA has three primary types of handoff:

hard soft idle The type of handoff depends on the handoff situation.

Soft handoff

A soft handoff establishes a connection with the new BTS prior to breaking the connection with the old one. This is possible because CDMA cells use the same frequency and because the mobile uses a rake receiver.

The CDMA mobile assists the network in the handoff. The mobile detects a new pilot as it travels to the next coverage area. The new base station then establishes a connection with the mobile. This new communication link is established while the mobile maintains the link with the old BTS.

Soft handoffs are also called "make-before-break."

Variations of the soft handoff

There are two variations of soft handoffs involving handoffs between sectors within a BTS:

Softer Soft-softer

The softer handoff occurs between two sectors of the same BTS. The BTS decodes and combines the voice signal from each sector and forwards the combined voice frame to the BSC. The soft-softer handoff is combination handoff involving multiple cells and multiple sectors within one of the cells.

CDMA hard handoff

A hard handoff requires the mobile to break the connection with the old BTS prior to making the connection with the new one. CDMA phones use a hard handoff when moving from a CDMA system to an analogue system because soft handoffs are not possible in analogue systems. 

A Pilot Beacon Unit (PBU) at the analogue cell site alerts the phone that it is reaching the edge of CDMA coverage. The phone switches from digital to analog mode as during the hard handoff.

Hard handoffs are also called "break-before-make."

When does CDMA use a hard handoff?

The CDMA hard handoff may be used when moving from a CDMA network to an analogue one. It may also be used when moving to a different:

RF channel MTSO Carrier Market

Analog to CDMA handoff is not available due to the limitations of analog technology.

CDMA idle handoff

An idle handoff occurs when the phone is in idle mode. The mobile will detect a pilot signal that is stronger than the current pilot. The mobile is always searching for the pilots from any neighbouring BTS. When it finds a stronger signal, the mobile simply begins attending to the new pilot.

An idle handoff occurs without any assistance from the BTS.

5. Advantages of CDMA CDMA technology has numerous advantages including:

Coverage Capacity Clarity Cost Compatibility

Coverage

CDMA's features result in coverage that is between 1.7 and 3 times that of TDMA:

Power control helps the network dynamically expand the coverage area. Coding and interleaving provide the ability to cover a larger area for the same amount of available power used in other systems.

Clarity

Often CDMA systems can achieve "wire line" clarity because of CDMA's strong digital processing.

Specifically:

The rake receiver reduces errors The variable rate vocoder reduces the amount of data transmitted per person, reducing interference. The soft handoff also reduces power requirements and interference. Power control reduces errors by keeping power at an optimal level. CDMA's wide band signal reduces fading. Encoding and interleaving reduce errors that result from fading.

Cost

CDMA's better coverage and capacity result in cost benefits:

Increased coverage per BTS means fewer re needed to cover a given area. This reduces infrastructure costs for the providers. Increased capacity increases the service provider's revenue potential.

CDMA costs per subscriber has steadily declined since 1995 for both cellular and PCS applications.

Compatibility

CDMA phones are usually dual mode. This means they can work in both CDMA systems and analogue cellular systems.

Some CDMA phones are dual band as well as dual mode. They can work in CDMA mode in the PCS band, CDMA mode in the cellular band, or analog mode in an analog cellular network.

6. Customer benefits CDMA results in greater customer satisfaction because CDMA provides better:

Good voice quality Longer battery life due to reduced power requirements No cross-talk because of CDMA's unique coding Privacy, because of coding. WAP features High speed data transmission