Releases 8 and 9 of 3GPP covered the functionalities required to support the Home Node B (HNB) and Home eNodeB (HeNB). The new release aims to take these further and adds functionalities that will enable the mobile operators to provide services in a more effective manner, improving overall user experience. Several existing requirements on TS 22.220 which could not be realized in the previous stages are re-introduced. These are expected to be covered with Rel-10. This includes "Managed Remote Access to home based network", and "IMS Inter-working". It also features work on the studies related to machine-to-machine communications which enable network operators to offer machine-type communication services at a low cost level, to match the expectations of mass-market machine-type services and applications.Rel-10 aims to provide mechanisms enabling operator's control on routing of active PDN connections across available accesses. Another important feature is a solution to enable the operators seamlessly offload their traffic via IP flow mobility on to a WLAN. Operators will be able to use WLAN as a seamless extension of their cellular access and thus increase the overall system capacity while minimizing the access cost. On the RAN front, amendment of the 1.28Mcps TDD Home NodeB related specifications is proposed so as to support the Home NodeBs application.
The detailed overview of the specification is available from 3GPP.
Showing posts with label LTE. Show all posts
Showing posts with label LTE. Show all posts
Thursday, April 22, 2010
Wednesday, April 21, 2010
3GPP Picks Femtocell Standards
The 3rd Generation Partnership Project (3GPP) standards body has finally adopted an official architecture and started work on a new standard for home base stations. The specification for the interface between the Home Node B (HNB, the 3GPP term for femtocell) is being decided. The new interface will be called Iu-h and is a blend of existing standards Iu and generic access network (GAN), sometimes referred to as unlicensed mobile access (UMA). The 3GPP chose the solution backed by industry majors Alcatel-Lucent , Kineto Wireless Inc. , and its partners Motorola and NEC Corp. The new standard, which forms part of 3GPP’s Release 8, and interdependent with Broadband Forum extensions to its Technical Report-069 (TR-069), has been completed in just 12 months following close cooperation between 3GPP, the Femto Forum and the Broadband Forum.
Femtocells
The term has already been introduced to in one of the earlier posts. Femtocells are low-power wireless access points that operate in licensed spectrum to connect standard mobile devices to a mobile operator’s network using residential DSL or cable broadband connections.A Home Node B (HNB), is the 3GPP's term for a 3G femtocell. A Node B is an element of a 3G macro Radio Access Network (RAN). A femtocell performs many of the function of a Node B, but is optimized for deployment in the home.
The new standard
The new standard covers the following main areas:
Femtocells
The term has already been introduced to in one of the earlier posts. Femtocells are low-power wireless access points that operate in licensed spectrum to connect standard mobile devices to a mobile operator’s network using residential DSL or cable broadband connections.A Home Node B (HNB), is the 3GPP's term for a 3G femtocell. A Node B is an element of a 3G macro Radio Access Network (RAN). A femtocell performs many of the function of a Node B, but is optimized for deployment in the home.
The new standard
The new standard covers the following main areas:
- Network architecture
- Radio & interference aspects
- Femtocell management / provisioning and security
Friday, March 19, 2010
VoLTE - Voice over LTE
The need for a low-cost, low-risk approach for bringing Voice to LTE deployments have lead to an initiative by T-Mobile Germany and some of the leading equipment vendors (Cisco, Kineto, Motorola, Ericsson, and Alcatel-Lucent etc.) to enable transmission of voice over LTE networks. The solution will enable the delivery of traditional circuit switched services such as voice, SMS and VMS over LTE. The overall objective is to enable GSM/UMTS operators to re-use existing equipment to deliver circuit based services over LTE and hence reduce costs.The advantage is that it will minimize the number of elements required to deploy VoIP over LTE. The architecture will also support handoff of circuit based services between GSM/UMTS and LTE networks. This means operators with legacy networks can migrate some of their network to LTE, still supporting legacy services in rural and suburban areas. It will also enable roaming between LTE and GSM/UMTS networks.
Approaches
LTE (Long-Term Evolution) is shaping up as the choice of most mobile operators worldwide for next-generation networks, but it is not designed currently to carry voice or SMS traffic in the same way today's carrier networks do. This is basically because it uses a packet-based IP (Internet Protocol) data network. When looking at the options for ways of carrying voice over LTE, a number of possible solutions were arrived at. Equipment vendors and carriers have been lining up around two approaches to handle voice on LTE, called VoLGA (Voice over LTE via Generic Access) and One Voice.CSFB, Circuit Switched Fall Back is a less popular alternative.
Nokia Siemens Networks claims to have carried out a voice call over LTE networks at its research and development centers, recently. The call used the company's Fast Track VoLTE technology, which it said is aligned with the One Voice initiative. Meanwhile, Deutsche Telekom also claimed it had completed an LTE voice call using VoLGA technology, using independent VoLGA-based systems from Kineto Wireless and Alcatel-Lucent. Kineto has announced a new release of software for its access gateway that the company said supports the VoLGA Forum's specification.
The One Voice
The One Voice profile for Voice over LTE is proposed by a collaboration between over forty operators including: AT&T, Verizon Wireless, Nokia and Alcatel-Lucent. At the 2010 GSMA Mobile World Congress, GSMA announced that they were supporting the One Voice solution to provide Voice over LTE. VoLTE, Voice over LTE is an IMS-based specification. Adopting this approach will enable it to integrate into the suite of applications that will become available on LTE.
VoLGA
The VoLGA standard is based on the existing 3GPP Generic Access Network (GAN) standard. It aims at enabling LTE users to receive a consistent set of voice, SMS (and other circuit-switched) services as they transition between GSM, UMTS and LTE access networks.
CSFB, Circuit Switched Fall Back
The circuit switched fallback(CSFB) LTE has been standardised under 3GPP specification 23.272. LTE CSFB uses a variety of processes and network elements to enable the circuit to fall back to the 2G or 3G connection before a circuit switched call is initiated. It also allows for SMS to be carried since it is essential for set-up procedures for cellular telecommunications. The handset uses an interface known as SGs which allows messages to be sent over an LTE channel.
In the future, mobile operators with LTE will have to carry voice and SMS traffic alongside data on a single network using LTE. This will make more efficient use of radio spectrum. But the transition to that point is still very far!
Approaches
LTE (Long-Term Evolution) is shaping up as the choice of most mobile operators worldwide for next-generation networks, but it is not designed currently to carry voice or SMS traffic in the same way today's carrier networks do. This is basically because it uses a packet-based IP (Internet Protocol) data network. When looking at the options for ways of carrying voice over LTE, a number of possible solutions were arrived at. Equipment vendors and carriers have been lining up around two approaches to handle voice on LTE, called VoLGA (Voice over LTE via Generic Access) and One Voice.CSFB, Circuit Switched Fall Back is a less popular alternative.
Nokia Siemens Networks claims to have carried out a voice call over LTE networks at its research and development centers, recently. The call used the company's Fast Track VoLTE technology, which it said is aligned with the One Voice initiative. Meanwhile, Deutsche Telekom also claimed it had completed an LTE voice call using VoLGA technology, using independent VoLGA-based systems from Kineto Wireless and Alcatel-Lucent. Kineto has announced a new release of software for its access gateway that the company said supports the VoLGA Forum's specification.
The One Voice
The One Voice profile for Voice over LTE is proposed by a collaboration between over forty operators including: AT&T, Verizon Wireless, Nokia and Alcatel-Lucent. At the 2010 GSMA Mobile World Congress, GSMA announced that they were supporting the One Voice solution to provide Voice over LTE. VoLTE, Voice over LTE is an IMS-based specification. Adopting this approach will enable it to integrate into the suite of applications that will become available on LTE.
VoLGA
The VoLGA standard is based on the existing 3GPP Generic Access Network (GAN) standard. It aims at enabling LTE users to receive a consistent set of voice, SMS (and other circuit-switched) services as they transition between GSM, UMTS and LTE access networks.
CSFB, Circuit Switched Fall Back
The circuit switched fallback(CSFB) LTE has been standardised under 3GPP specification 23.272. LTE CSFB uses a variety of processes and network elements to enable the circuit to fall back to the 2G or 3G connection before a circuit switched call is initiated. It also allows for SMS to be carried since it is essential for set-up procedures for cellular telecommunications. The handset uses an interface known as SGs which allows messages to be sent over an LTE channel.
In the future, mobile operators with LTE will have to carry voice and SMS traffic alongside data on a single network using LTE. This will make more efficient use of radio spectrum. But the transition to that point is still very far!
Monday, March 1, 2010
Evolving HSPA : HSPA+
An evolution of HSPA has been specified based on the studies, which added multiple input/ multiple output (MIMO) antenna capability and 16QAM (Uplink)/ 64QAM (Downlink) modulation. The improvements in the radio access network for continuous packet connectivity will help the evolving architecture - HSPA+ - achieve uplink speeds of 11Mbps and Downlink speeds of 42Mbps. HSPA+, also known as Evolved High-Speed Packet Access is a wireless broadband standard defined in 3GPP release 7. The 3GPP roadmap from HSPA to HSPA+ and then to LTE has been well defined in standards development work with the final closing of Release 8.
HSPA+
HSPA+ is a simple upgrade to HSPA networks existing today. HSPA+ provides a performance advantage for the GSM-HSPA operators providing OFDMA equivalent performance in 5X5 MHz spectrum allocations
with only incremental investment.HSPA+ doubles the data capacity over HSPA and over WCDMA, it offers more than double voice capacity. Lower latency is being projected as one of the key advantages. Higher order modulation schemes are utilized to enhance the data rates. HSPA+ networks are likely to co-exist with LTE networks during the initial years, after which the oprerators may want to shift to the next level of efficiency. The discontinuous transmit/receive feature allows the device to gate off the control channels when there is no user data to send. Similarly the receiver is turned off at certain agreed intervals when there is no downlink information to the device. Such a synchronized operation allows the device to shut off its transmitter and receiver blocks completely, which significantly improves the device battery life for voice over HSPA services.
HSPA+ thus provides an excellent technology evolution path from HSPA, enabling operators to maximize their return on existing investments.
HSPA+
HSPA+ is a simple upgrade to HSPA networks existing today. HSPA+ provides a performance advantage for the GSM-HSPA operators providing OFDMA equivalent performance in 5X5 MHz spectrum allocations
with only incremental investment.HSPA+ doubles the data capacity over HSPA and over WCDMA, it offers more than double voice capacity. Lower latency is being projected as one of the key advantages. Higher order modulation schemes are utilized to enhance the data rates. HSPA+ networks are likely to co-exist with LTE networks during the initial years, after which the oprerators may want to shift to the next level of efficiency. The discontinuous transmit/receive feature allows the device to gate off the control channels when there is no user data to send. Similarly the receiver is turned off at certain agreed intervals when there is no downlink information to the device. Such a synchronized operation allows the device to shut off its transmitter and receiver blocks completely, which significantly improves the device battery life for voice over HSPA services.
HSPA+ thus provides an excellent technology evolution path from HSPA, enabling operators to maximize their return on existing investments.
Wednesday, February 17, 2010
3GPP networks : shrinking the globe further
A new survey by the Global mobile Suppliers Association (GSA) published recently confirms the increased penetration of GSM/EDGE systems.Operators in a large number of regions have made significant investments to enhance the capacity and coverage of their existing networks.The common trend has been to extend EDGE capabilities to the full GSM coverage areas.After the first commercial EDGE network deployment in June 2003, GSA estimates that over 80% of GPRS operators have committed to the EDGE enhancement.EDGE network capabilities are evolving as part of the 3GPP specifications. Commercial EDGE Evolution solutions are now available which increase EDGE network downlink and uplink data speeds and reduce latency, extending mobile broadband availability cost-effectively.
On the wireless broadband front the UMTS Forum confirms that subscriptions to 3G/UMTS networks have reached 500 million. The milestone has been achieved in just eight years after the world’s first commercial 3G/WCDMA network was deployed by Japanese operator NTT DOCOMO. According to data from wireless Intelligence (http://www.wirelessintelligence.com), there are now over 300 UMTS family networks worldwide.The total includes almost 40% of 3G/UMTS subscribers who are enjoying an enhanced mobile broadband experience via HSPA networks. Over 35 HSPA+ networks are now commercialized, boosting theoretical peak data rates as high as 28 Mb/sec.It is amazing to note that it took fixed telephone networks over a century to reach their first half billion customers. GSM networks have achieved the same milestone in only a decade!. This clearly is a reflection of the modern world's ever-growing need to stay connected. WCDMA and now HSPA are delivering the same services at a cost that made GSM a global success. Building on the success of the WCDMA/HSPA systems, LTE is expected to offer end-users an even faster, more satisfying mobile Internet experience, while attracting a new wave of players from new frontiers.
On the wireless broadband front the UMTS Forum confirms that subscriptions to 3G/UMTS networks have reached 500 million. The milestone has been achieved in just eight years after the world’s first commercial 3G/WCDMA network was deployed by Japanese operator NTT DOCOMO. According to data from wireless Intelligence (http://www.wirelessintelligence.com), there are now over 300 UMTS family networks worldwide.The total includes almost 40% of 3G/UMTS subscribers who are enjoying an enhanced mobile broadband experience via HSPA networks. Over 35 HSPA+ networks are now commercialized, boosting theoretical peak data rates as high as 28 Mb/sec.It is amazing to note that it took fixed telephone networks over a century to reach their first half billion customers. GSM networks have achieved the same milestone in only a decade!. This clearly is a reflection of the modern world's ever-growing need to stay connected. WCDMA and now HSPA are delivering the same services at a cost that made GSM a global success. Building on the success of the WCDMA/HSPA systems, LTE is expected to offer end-users an even faster, more satisfying mobile Internet experience, while attracting a new wave of players from new frontiers.
Wednesday, February 3, 2010
LTE is IMT advanced - 3GPP
In September 2009 the 3GPP Partners made a formal submission to the ITU proposing that LTE Release 10 and successors (called LTE-Advanced) be evaluated as a candidate for IMT-Advanced. This suggests that the next generation or truly 4G mobile WiMAX is likely to be a specification that is never implemented on a significant scale. This news may be confusing to those who thought that lot of operators have already deployed "4G" WiMAX networks. Since the backwards compatibility of 802.16m with current 802.16e is being emphasized, the hopes that somehow LTE and mobile WiMAX might be merged, or that the latter could become the TDD version of LTE has been put to rest. Operators now installing and committed to 802.16e should be very wary about the long term roadmap for mobile WiMAX technology. They should ensure that they do not lock themselves into this technology for very long, and should be preparing paths for migration to LTE. Intel has been a champion of WiMAX since its inception. But Intel’s future in mobile product markets is much more dependent upon its ability to carve out a substantial share for its low power processors in this business and to have its components incorporated into devices that will work on 3GPP networks, than it is upon the supply of chipsets for WiMAX wireless modems. LTE supports voice and efficient support of voice was one of the key considerations in designing LTE. The voice solution for LTE is IMS VoIP and it is fully specified.
Wednesday, January 27, 2010
Single Carrier FDMA - for 4G wireleess
Over the last decade, the bit rates achieved in wireless communications systems have increased steadily.
TDMA and CDMA has been the major technologies in multiple access. The highest bit rates in commercially deployed wireless systems are achieved by means of Orthogonal Frequency Division Multiplexing (OFDM). The next advance in cellular systems, under investigation by the Third Generation Partnership Project (3GPP), also anticipates the adoption of OFDMA to achieve higher bit rates. Single carrier frequency division multiple access (SC-FDMA), a modified form of Orthogonal FDMA (OFDMA), is a promising technique for high data rate up-link communications in future cellular systems.
SC FDMA
An SC system transmits a single carrier, modulated, for example, with QAM, at a high symbol rate. The transmitters use different orthogonal subcarriers to transmit information symbols. The transmission is sequential, which reduces the variations in the transmitted signal envelope. This results in a lower peak-to-average-power ratio. Frequency domain equalization os carried out to counter the severe delay spreads the signal might encounter. The advantages may be listed as:
SC-FDMA transmitter and receiver
The block diagram of the SC-FDMA receiver and transmitter is given the figure. The figure is self-explanatory. Similar to OFDM modulation, DFTS-OFDM relies on block-based signal generation.
By adjusting the transmitter DFT size and the size of the block of modulation symbols the nominal bandwidth of the DFTS-OFDM signal can be dynamically adjusted.
Throughput
Information throughput is another indication of the system performance. Here the throughput depends on the manner in which information is applied to the subcarriers. The two main methods are localized and distributed. The benefit of distributed system, compared to localized, is the possibility for additional frequency diversity as even a low-rate distributed signal can be spread over a potentially very large overall transmission bandwidth. It has been shown that the SC-FDMA can be tuned to achieve data rates in excess of 40Mbps.
Future
Within a specific SC-FDMA system configuration, there are many design and operational choices that affect performance in a complex manner . The impact of channel estimation error on the throughput performance of SC-FDMA is still not understood clearly. Still, SC-FDMA is a promising technique for high data rate
uplink communication in future cellular systems.
TDMA and CDMA has been the major technologies in multiple access. The highest bit rates in commercially deployed wireless systems are achieved by means of Orthogonal Frequency Division Multiplexing (OFDM). The next advance in cellular systems, under investigation by the Third Generation Partnership Project (3GPP), also anticipates the adoption of OFDMA to achieve higher bit rates. Single carrier frequency division multiple access (SC-FDMA), a modified form of Orthogonal FDMA (OFDMA), is a promising technique for high data rate up-link communications in future cellular systems.
SC FDMA
An SC system transmits a single carrier, modulated, for example, with QAM, at a high symbol rate. The transmitters use different orthogonal subcarriers to transmit information symbols. The transmission is sequential, which reduces the variations in the transmitted signal envelope. This results in a lower peak-to-average-power ratio. Frequency domain equalization os carried out to counter the severe delay spreads the signal might encounter. The advantages may be listed as:
- Small variations in the instantaneous power of the transmitted signal
- Possibility for low-complexity high-quality equalization in the frequency domain.
- Possibility for FDMA with flexible bandwidth assignment.
- SC-FDMA can be seen as normal OFDM with a DFT-based precoding
SC-FDMA transmitter and receiver
The block diagram of the SC-FDMA receiver and transmitter is given the figure. The figure is self-explanatory. Similar to OFDM modulation, DFTS-OFDM relies on block-based signal generation.
By adjusting the transmitter DFT size and the size of the block of modulation symbols the nominal bandwidth of the DFTS-OFDM signal can be dynamically adjusted.
Throughput
Information throughput is another indication of the system performance. Here the throughput depends on the manner in which information is applied to the subcarriers. The two main methods are localized and distributed. The benefit of distributed system, compared to localized, is the possibility for additional frequency diversity as even a low-rate distributed signal can be spread over a potentially very large overall transmission bandwidth. It has been shown that the SC-FDMA can be tuned to achieve data rates in excess of 40Mbps.
Future
Within a specific SC-FDMA system configuration, there are many design and operational choices that affect performance in a complex manner . The impact of channel estimation error on the throughput performance of SC-FDMA is still not understood clearly. Still, SC-FDMA is a promising technique for high data rate
uplink communication in future cellular systems.
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