Radiomovel - Code-Division Multiple Access-Wireless Local Loop, Portugal
Radiomovel, the Portuguese subsidiary of Inquam, rolled out a new Code-Division Multiple Access-Wireless Local Loop (CDMA-WLL) 450 network across Portugal in 2003–2004.
Inquam chose Huawei Technologies Company Ltd as the contractor to build the network and provide handsets to work under the same standard. The network, completed final construction and commissioning during July 2004, and became fully operational shortly afterwards.
This network was the first commercial application of CDMA 450 in Western Europe. The system operates in the 450MHz frequency band previously occupied by analogue Nordic Mobile Telephony (NMT) systems.
CDMA 450 systems are part of the CDMA 2000 group of technologies currently being deployed worldwide. These include systems operating at 450MHz, and wideband systems operating at 850MHz, 1,800MHz and 2,100MHz.
The emerging popularity of CDMA 450 is due to the lower costs of deployment for this type of network. The investment for the infrastructure development in this project was estimated at $160m.
The Zapp network is the wireless data portion of the network and this operates (since 2005) with two technologies simultaneously, CDMA 1X RTT and CDMA 1X EV-DO.
In EV-DO mode the data transmission of the Zapp network reaches a speed of up to 1.4Mbps on downlink and 153kbps on uplink. In RTT mode the data transmission can reach a speed of up to 153kbps in both directions of transmission.
The Zapp telemodem is prepared to work on 1X EV-DO mode. Whenever the EV-DO is not available, the Zapp telemodem automatically changes to 1X RTT mode.
CDMA 450 ADVANTAGES
CDMA 450 is a 3G technology which uses CDMA 2000 1X air interface. The main advantages of this are:
- 450MHz signals result in lower propagation loss and so can yield a broader coverage than higher frequencies in the same CDMA 2000 group
- Broader coverage means that up to 80% fewer base stations are required for the network and thus the cost of infrastructure development is much lower
- Coverage for CDMA 450 is up to 50km, whereas in comparison W-CDMA has a propagation range of only 2km
- CDMA 450 has data speeds approaching 2.4Mbps (Huawei have achieved 1.9Mbps in trials) and can support a range of services such as push-to-talk, location-based services and UIM, the GSM compatible SIM card
- With CDMA's standard 1.25MHz channels the 450MHz band gives excellent capacity
- UIM support means that CDMA 450 roaming should also be possible in the future
- It is a cost-effective way for countries with large rural areas to bring 3G services to the majority of their population
- CDMA 450 is also fully compatible with future upgrade paths such as EV-DO 1X and EV-DV 1X
CDMA 450 NETWORKS
Inquam, the parent company of Radiomovel, was set up by UK-based Qualcomm in 2002 to purchase old defunct NMT 450 networks and migrate them to CDMA 450 technology. Huawei, a Chinese telecommunications company, specialises in providing CDMA 450 technology and has deployed networks across 43 countries worldwide, many of them in Eastern Europe.
Huawei and Inquam formed a strategic partnership in 2002 to develop CDMA 450 networks across Europe.
Huawei, as part of this arrangement, was contracted by Radiomovel to supply and install a CDMA 450 end-to-end network early in 2003 (including terminals and handsets).
Huawei supplied its C&C08 iNET International Mobile Telecommunications-2000 (IMT2000)-based base station and serialised terminals.
It is also provided some of the location-based services to be provided by Radiomovel, such as GPSOne, high-speed packet data services and multimedia services such as video phone, Video On Demand (VOD) and internet access, aside from the basic voice and messaging services the company provides.
Both V5.2 and SS7 interfaces are provided to meet the different networking needs of new business subscribers. The system also includes WLL capability, which can connect subscribers to the Public Switched Telephone Network (PSTN) using radio signals as a substitute for the copper wire connection between the subscriber and the switch. This helps to connect subscribers in very rural parts of the country that have an inefficient or non-existent telephone service.
MOTOROLA SOFT SWITCH FOR CODE DIVISION MULTIPLE ACCESS
The deployment of the network was not the end of the story for Radiomovel; they also needed equipment and software from other sources to offer all the services they intended. Motorola agreed in October 2003 to supply, install and commission its Motorola Soft Switch for Code Division Multiple Access (MSS-C). The software-based system was installed and commissioned in the core network by early 2004.
The scalability of this system allows Radiomovel to boost their capacity as the number of subscribers to the new system increases. The MSS-C is a highly scalable packet-based platform with power consumption three times less and physical size five times smaller than a traditional circuit switch, making it less expensive to operate.
The open architecture of the MSS-C is built on the same platform as the Motorola IP Multimedia System (IMS) and Push-To-Talk (PTT) systems, allowing easy cost effective upgrade to these systems if required in the future.
The CDMA interface between the Motorola radio access network and the softswitch is fully compliant with the InterOperability Specification (IOS) open standard.
Telecommunication Systems was contracted by Radiomovel to supply and install a CDMA Assisted Global Positioning System (AGPS) allowing Radiomovel to provide a wider variety of location-based services to a growing number of subscribers throughout Portugal.
The company supplied its Xypoint Location Platform (XLP) for CDMA networks which included Mobile Positioning Centre (MPC) and Position Determining Entity (PDE) functionality.
The MPC processes location requests from handset-based or network-based applications and is assisted by the PDE which executes APGS algorithms in conjunction with mobile devices to calculate the precise location.
This function enables the deployment of network-based enterprise applications such as fleet tracking and handset-based business applications.
FORSK SOFTWARE PLANNING NETWORK UPGRADE
In November 2005, Forsk was contracted to supply their 'Atoll' software system for the RF design of the CDMA 2000 450MHz network. RadioMovel also selected Atoll#153; Microwave for the design of its microwave transmission network.
RadioMovel were looking into upgrading to EV-DO and needed a tool able to help them design their CDMA 2000 1xRTT/EV-DO network. Atoll was the most appropriate software for this.
Atoll Microwave, a microwave planning software fully integrated with the RF planning tool was also chosen. The software allows a better exchange of information between the RF planning and transmission planning teams. Forsk provided licenses and well as user training, installation and configuration services.
CDMA 450 MHZ HANDSETS
At the time of installation the number of 450MHz handsets was limited. The CDMA 450 system has since been widely adopted and large handset manufacturers have embraced this technology, producing 450MHz versions of their CDMA handsets.
There are even dual-, triple- and quad-band versions of handsets for full worldwide roaming, although, the 450MHz handset market has continued to be dominated by Chinese and Taiwanese suppliers. Huawei handsets were the first used on the Radiomovel network.