UMTS vs. WCDMA- What is the difference?

If you are interested in third generation cellular networking technologies, then you have come to the right place. Here in is an elaborate review of UMTS and WCDMA, take a look.

3G, or the third generation of cellular communications has a long history of upgrades and changes. Both UMTS and WCMDA are part of this evolution: specifically the 3GPP initiative. Due to various capacity limitations on 2G networks, ITU-R among other bodies saw it to develop a more reliable standard which accommodates higher data rates and overall better suited to meet user demands.

These changes are designed to help maximize the potential of 3G networks. Ideally, UMTS, the Universal Mobile Telecommunications systems, is the next standard in line after the popular GSM and EDGE standards on the 2G’s network technology arsenal.

While the core network architecture is similar to the 2G network, 3G UMTS is based on different radio interface which offers wider, more efficient transmission channels. This change is what is known as WCDMA in telecommunications: Wide Code Division Multiple Access.

What are the differences between UMTS and WCDMA?

So what does a 3G UMTS WCDMA network look like?

The networking standard UMTS, utilizes the newer radio access technology, WCDMA. They are technically not the same thing since UMTS refers to cellular technology while WCDMA describes one of air interfaces on which 3G UMTS operates.

These terms are used interchangeably to describe the radio technologies developed on 3GPP specifications for the third generation network.

UMTS vs. WCDMA – A comparison review

UMTS

2G, is the second generation of cellular networks which was built on technologies such as GSM, CDMA and EDGE (in the later years). It is upon these standards and tech that 3G UMTS is founded. Ideally, 3G evolved to allow transmission of data over a wide spectrum. These upgrades are designed to allow integration of wider radio access with better spectral efficiency, better switching techniques and multimedia data types. In fact, UMTS supports a wider variety of data rates, with switching evolved to accommodate packet and circuit switching service.

UTMS is available in two modes: FDD and TDD, with 3 main subsystems on the network architecture. These explain the 3 main levels with which UTMS operates including, UE interface where the user interacts with the technology, UTRAN (level which includes WCDMA interface), and the Core Network interface that handles various operation functions like switching, routing and tracking.

This standard represents a smooth transition from GSM operations, since the core network architecture does not drastically change. By reusing GMS, GPRS architectures, many carriers/vendors reused the equipments and layouts for 2G networks with some upgrades as needed.

Notably, the transmission technology on UTMS evolved in later years from WCDMA to other more efficient systems. It also represents the upgrade to HSPDA and an all IP defined network as we have seen in later 3G networking technologies, including LTE; an all IP based standard. High Speed Downlink Packet Access, which is built on core UTMS standards, is the real turning point for 3G networks which enabled a leap in transmission rates on 3G from WCDMA’s 384kbps to 3.6Mbps, 7.2Mbps and upwards. With these upgrades, 3G networks featured improved capacity, with more bandwidth and even lower latency.

Some of the benefits UMTS brought to 3G connectivity include optimization of the 2G network by maximizing the potential said networks. Additionally, 3G UTMS allows more capacity on the network compared to older 2G technologies.

Security features on UMTS are based off of elements from GSM. The technology includes some few additions including authentication and encryption features. These help increase security and reliability over 3G networks. Basic security functions on UMTS aside from GSM security include subscriber identification functions, with identification confidentiality. Moreover, security functions on 3G UTMS SIM cards with PIN identification in addition to radio interface encryption.

WCDMA

Developed as part of the IMT-2000 standards, Wideband Code Division Multiple Access is designed as the radio/air interface for UMTS. With this, users can access wider ranges of data rates using the spreading codes.

WCDMA utilizes the techniques on traditional CDMA but features various improvements like a wider bandwidth, and different control channels and signaling. Channelization codes and scrambling allows for the separation of transmissions originating from the same source. These two physical layer spreading steps produce WCDMA signals.

Over this technology, data is encoded using a spreading code given to every user. With this, only the desired user can correlate and decode their signal. Multiple users can therefore utilize the same RF channel simultaneously. WDCMA is meat to allow many channels and users to operate without any interference. Ideally, WDMA operates on 5-Mhz channels with accommodations for multiple deployment and use as we have explained. The maximum chip rate achieved over WCDMA IS 3.84Mchips/s.

Thanks to WCDMA developments, operators get to redesign channel bandwidths to suit user needs best. Different techniques in handovers, code management and even traffic management make WCDMA widely better compared to the original CDMA. The result is a more robust and interference resistant air interface.

Because it operates on a wider bandwidth, WCDAM allows for multiple access and overall greater capacity on 3G networks.  Some of the performance specifications on WCDMA include peak download and upload speeds of 384kbps, and 128kbps respectively. Over 3G UMTS (WCDMA), users can enjoy an approximate roundtrip time of 150ms, compared to 2G’s latency: these connections are highly responsive.

Conclusion

It is easy to confuse all the abbreviations and jargon used to describe the different technologies developed to improve 3G networks. Both these technologies represent evolutionary milestones, and foundations for even faster cellular networking technologies. With the article above, users should be able to differentiate between the 3G’s cellular technology UMTS from the radio interface upon which this is based: WCDMA.

 FAQs

Is 3g and UMTS the same?

UMTS describes the evolution within 3G networks from the GSM standard.

What network is WCDMA?

Wideband CMDA is a newer radio access technology developed under 3GPP specifications to serve and improve 3G networking.