India’s telecom standards organization TSDSI has submitted its candidate Radio Interface Technology (RIT) to the IMT-2020 evaluation at the ITU-R WP 5D meeting #32 being held in Buzios, Brazil from 9 July 2019 to 17 July 2019. TSDSI’s IMT 2020 submission is one of five candidate RIT proposals- see NOTE at bottom of this article for more information.
TSDSI’s RIT is described in document ITU-R WP5D-AR Contribution 770. This RIT has been developed to address the rural requirements by enabling the implementation of Low Mobility Large Cell (LMLC), particularly with emphasis on low-cost rural coverage of 5G wireless network services. TSDSI believes that this RIT will also help to meet the rural requirements of other developing countries. We agree!
TSDSI proposal on Low Mobility Large Cell (LMLC) configuration has been included as a mandatory test configuration under the Rural eMBB (enhanced Mobile BroadBand) test environment in IMT 2020 Technical Performance Requirements (TPR) in ITU-R with an enhanced Inter Sire Distance (ISD) of 6 km. Incorporation of LMLC in IMT2020 will help address the requirements of typical Indian rural settings and will be a key enabler for bridging the rural-urban divide with 5G rollouts.
–>The Indian administration (ITU member country) extends its support to the RIT of TSDSI and solicits the support of ITU Member States to support this proposal.
Indian wireless network operators, including Reliance Jio Infocomm Ltd, have expressed interest in LMLC.
Kiran Kumar Kuchi, a professor at IIT Hyderabad is building a 5G testbed there. The system will exceed IMT 2020 5G performance requirements including Low Mobility Large Cell.
IIT Hyderabad 5G Testbed. Photo courtesy of IIT Hyderabad.
TSDSI’s baseline RIT (initial description template) is documented in ITU-R WP 5D Document 5D/980: Revision 2 to Document IMT-2020/7-E, submitted on 14 February 2019. Several updates to TSDSI RIT included the updated characteristics template, initial link budget template, etc. They are in Document 5D/1138: Attachment Part 1: 5D/1138!P1; Attachment Part 2: 5D/1138!P2; Attachment Part 3: 5D/1138!P3; Attachment Part 4: 5D/1138!P4)
Here are a few key excerpts from the TSDSI baseline RIT:
Describe details of the radio interface architecture and protocol stack such as: – Logical channels – Control channels – Traffic channels Transport channels and/or physical channels.
RAN/Radio Architectures: This RIT contains NR standalone architecture. The following paragraphs provide a high-level summary of radio interface protocols and channels.
Radio Protocols: The protocol stack for the user plane includes the following: SDAP, PDCP, RLC, MAC, and PHY sublayers (terminated in UE and gNB). On the Control plane, the following protocols are defined: – RRC, PDCP, RLC, MAC and PHY sublayers (terminated in UE and gNB); – NAS protocol (terminated in UE and AMF) For details on protocol services and functions, please refer to 3GPP specifications (e.g. [38.300]).
Radio Channels (Physical, Transport and Logical Channels):
- The physical layer offers service to the MAC sublayer transport channels. The MAC sublayer offers service to the RLC sublayer logical channels.
- The RLC sublayer offers service to the PDCP sublayer RLC channels.
- The PDCP sublayer offers service to the SDAP and RRC sublayer radio bearers: data radio bearers (DRB) for user plane data and signalling radio bearers (SRB) for control plane data.
- The SDAP sublayer offers 5GC QoS flows and DRBs mapping function.
The physical channels defined in the downlink are: – the Physical Downlink Shared Channel (PDSCH), – the Physical Downlink Control Channel (PDCCH), – the Physical Broadcast Channel (PBCH).
The physical channels defined in the uplink are: – the Physical Random Access Channel (PRACH), – the Physical Uplink Shared Channel (PUSCH), – and the Physical Uplink Control Channel (PUCCH). In addition to the physical channels above, PHY layer signals are defined, which can be reference signals, primary and secondary synchronization signals.
The following transport channels, and their mapping to PHY channels, are defined:
Uplink: – Uplink Shared Channel (UL-SCH), mapped to PUSCH – Random Access Channel (RACH), mapped to PRACH
Downlink: – Downlink Shared Channel (DL-SCH), mapped to PDSCH – Broadcast channel (BCH), mapped to PBCH – Paging channel (PCH), mapped to (TBD)
Logical channels are classified into two groups: Control Channels and Traffic Channels.
Control channels: – Broadcast Control Channel (BCCH): a downlink channel for broadcasting system control information. – Paging Control Channel (PCCH): a downlink channel that transfers paging information and system information change notifications. – Common Control Channel (CCCH): channel for transmitting control information between UEs and network. – Dedicated Control Channel (DCCH): a point-to-point bi-directional channel that transmits dedicated control information between a UE and the network.
Traffic channels: Dedicated Traffic Channel (DTCH), which can exist in both UL and DL. In Downlink, the following connections between logical channels and transport channels exist: – BCCH can be mapped to BCH, or DL-SCH; – PCCH can be mapped to PCH; – CCCH, DCCH, DTCH can be mapped to DL-SCH;
In Uplink, the following connections between logical channels and transport channels exist: – CCCH, DCCH, DTCH can be mapped to UL-SCH.
1. Method to improve broadcast and paging control channel efficiency over access elements.
2. Reduce the impact of congestion in the data path and control path to improve overall efficiency in the network. Other aspects – NR QoS architecture The QoS architecture in NG-RAN (connected to 5GC), can be summarized as follows: For each UE, 5GC establishes one or more PDU Sessions. For each UE, the NG-RAN establishes one or more Data Radio Bearers (DRB) per PDU Session. The NG-RAN maps packets belonging to different PDU sessions to different DRBs. Hence, the NG-RAN establishes at least one default DRB for each PDU Session. NAS level packet filters in the UE and in the 5GC associate UL and DL packets with QoS Flows. AS-level mapping rules in the UE and in the NG-RAN associate UL and DL QoS Flows with DRBs – Carrier Aggregation (CA) In case of CA, the multi-carrier nature of the physical layer is only exposed to the MAC layer for which one HARQ entity is required per serving cell. – Dual Connectivity (DC) In DC, the radio protocol architecture that a radio bearer uses depends on how the radio bearer is setup.
Four bearer types (information carrying channels) exist: MCG bearer, MCG split bearer, SCG bearer and SCG split bearer.
The following terminology/definitions apply:
– Master gNB: in dual connectivity, the gNB which terminates at least NG-C.
– Secondary gNB: in dual connectivity, the gNB that is providing additional radio resources for the UE but is not the Master node.
– Master Cell Group (MCG): in dual connectivity, a group of serving cells associated with the MgNB
– Secondary Cell Group (SCG): in dual connectivity, a group of serving cells associated with the SgNB
– MCG bearer: in dual connectivity, a bearer whose radio protocols are only located in the MCG.
– MCG split bearer: in dual connectivity, a bearer whose radio protocols are split at the MgNB and belong to both MCG and SCG.
– SCG bearer: in dual connectivity, a bearer whose radio protocols are only located in the SCG.
– SCG split bearer: in dual connectivity, a bearer whose radio protocols are split at the SgNB and belong to both SCG and MCG.
In case of DC, the UE is configured with two MAC entities: one MAC entity for the MCG and one MAC entity for the SCG. For a split bearer, UE is configured over which link (or both) the UE transmits UL PDCP PDUs. On the link which is not responsible for UL PDCP PDUs transmission, the RLC layer only transmits corresponding ARQ feedback for the downlink data.
For more details on (3GPP “5G”) NR Radio Protocol architecture and channels, refer to: [38.300], [38.401], [38.201], [37.340] What is the bit rate required for transmitting feedback information? The information will be provided in later update.
Channel access: Describe in detail how RIT/SRIT accomplishes initial channel access, (e.g. contention or non-contention based).
Initial channel access is typically accomplished via the “random access procedure” (assuming no dedicated/scheduled resources are allocated). The random access procedure can be contention based (e.g. at initial connection from idle mode) or non-contention based (e.g. during Handover to a new cell). Random access resources and parameters are configured by the network and signaled to the UE (via broadcast or dedicated signaling). Contention based random access procedure encompasses the transmission of a random access preamble by the UE (subject to possible contention with other UEs), followed by a random access response (RAR) in DL (including allocating specific radio resources for the uplink transmission). Afterwards, the UE transmits the initial UL message (e.g. RRC connection Request) using the allocated resources, and wait for a contention resolution message in DL (to confirming access to that UE). The UE could perform multiple attempts until it is successful in accessing the channel or until a timer (supervising the procedure) elapses. Non-contention based random access procedure foresees the assignment of a dedicated random access resource/preamble to a UE (e.g. part of an HO command). This avoids the contention resolution phase, i.e. only the random access preamble and random access response messages are needed to get channel access.
From a L1 perspective, a random access preamble is transmitted (UL) in a PRACH, random access response (DL) in a PDSCH, UL transmission in a PUSCH, and contention resolution message (DL) in a PDSCH.
1. TSDSI’s RIT is one of five proposals for the IMT 2020 RIT/SRIT.
The other four are from: 3GPP, South Korea, China, and ETSI/DECT Forum. All but the latter are based on 3GPP “5G NR.”
- The Candidate RIT/SRIT submission from China, as acknowledged in IMT-2020/5, is technically identical to the 5G NR RIT submitted from 3GPP as acknowledged in IMT-2020/3.
- The candidate RIT/SRIT submission from South Korea, as acknowledged in IMT-2020/4, is technically identical to the 5G NR RIT submitted from 3GPP as acknowledged in IMT-2020/3.
2. 3GPP release 16:
As we have stated numerous times, 3GPP’s final IMT 2020 RIT/SRIT submission to ITU-R WP 5D will be largely based on 3GPP release 16 (with perhaps some elements of release 15 also included). From the 3GPP website:
Release 16 will meet the ITU IMT-2020 submission requirements and the time-plan as outlined in RP-172101.
Some Background on 3GPP Release 16:
- Early progress on Rel-16 bands for 5G
- “Working towards full 5G in Rel-16″…See a webinar presentation (Bright talk webinar)
- Preparing the ground for IMT-2020
- SA1 completes its study into 5G requirements
Here is the active status of 3GPP release 16 project.
The 3GPP release 16 completion date has been delayed by at least 3 months (1Q 2020) with no new completion date specified at this time.
3. DECT Forum/ETSI submission for IMT 2020 SRIT:
From a July 1, 2019 contribution to ITU-R WP5D Brazil meeting:
DECT Forum would like to announce its support and endorsement for the IMT-2020 contribution from ETSI for an SRIT candidate for inclusion in IMT-2020. The proposed SRIT consists of two component RITs:
⦁ DECT-2020 NR RIT
⦁ 3GPP 5G CANDIDATE FOR INCLUSION IN IMT-2020: SUBMISSION 2 FOR IMT-2020 (RIT)
DECT Forum confirms its continuation as a proponent of this IMT-2020 proposal.
by Muntazir Abbas (edited by Alan J Weissberger) from Economic Times:
India’s 5G ambition may be thwarted as mobile infrastructure expansion is likely to remain low-paced following policy bottlenecks in the federal governance structure. Add to that India’s weak fiberization, which is mandatory for high-speed wireless network backhaul.
The country’s existing telecom infrastructure catering to a billion active subscribers may require rapid expansion, but the absence of clarity on active network sharing, distributed right-of-way norms and thin fibre penetration, may not bring 2020 a true 5G year.
The Narendra Modi-led government is eyeing to make 5G services commercially available by next year after soon-to-start field trials which would be followed by a mega spectrum sale with 275 Mhz of airwaves earmarked for the newer technology.
Plagued with high debt, the telco incumbents Vodafone Idea and Bharti Airtel, have not made much network investments over the past few years. In a constrained scenario, sharing of active and passive networks assume much significance.
The Tower and Infrastructure Providers Association (Taipa) Director General Tilak Raj Dua says, “In order to make 5G a success story in India, it is essential to invest on network densification heavily through provisioning of fiber, small cells and mobile towers.” Taipa represents telecom infrastructure companies in the country.
The India Department of Telecommunications (DoT), over the past few years, has apparently not been able to bring telecom tower companies to mainstream despite their ever-growing role in India’s digital service delivery.
The much-sought ‘infrastructure status’ accorded to the sector in 2012, has not materialised so far with firms seeking the Narendra Modi government to bring about radical reforms before the 5G make a debut.
Fiberization— A must do
Fibre-based backhaul is still in infancy in India. Industry’s assessment suggests that India’s robust 5G network would require 100 million fibre kilometres (m fkm) optic-fibre cable a year which has been growing at merely a rate of nearly 25 mfkm a year currently.
The government has recognized it as the strategic element for a high-speed data network, and has put a huge thrust and aims to increase fibre footprint to five fold or 7.5 million kilometres by 2022, from the current 1.5 million kilometers. In addition, the national policy aims to fiberise at least 60% of telecom towers by 2022, eventually accelerating migration to 5G.
“Achieving such speeds make fiber connectivity essential. India’s high population density also translates into deeper and denser fiber network,” ratings agency ICRA in its finding said, adding that the country has about 500,000 towers of which only 22% are fiberised as against 80% in China.
Earlier, telecom secretary Aruna Sundararajan said that that the department would want to benchmark how much fibre is being deployed every day to achieve 4G and 5G, and it has to become a national priority, and added that if the industry ever wants to take 5G to the villages without fibre, it would not happen, as fiberisation remains a key driver.
State-run Bharat Sanchar Nigam Limited (BSNL) that has the largest fibre base of up to 8 lakh kilometres is considering to lease out dark fibre to private players in a run up to 5G rollout that according to analysts would help operators cut Capex by leveraging state telco’s infrastructure as per need basis.
ICRA estimates the present market value of fiber assets owned by major private telecom operators stand at nearly Rs 1.25 lakh crore, with the extent of fiber rollout over the next few years would require investments of Rs 2.5 lakh crore to 3 lakh crore and sharing of fiber among multiple telcos would be the driver for a reasonable return on capital.
“5G rollout is the biggest driver for all major investment into fibre infrastructure in next five years. The next generation of technology’s performance will be dependent on the overflow of content to and from data centres,” Sandeep Aggarwal, Managing Director of Paramount Communications said, and added that the only medium capable of meeting these demands is fiber which will need to be available at every nook and corner of the country.
The government, in a recently-unveiled national policy also talked about setting up of a National Fibre Authority (NFA), but ironically there has been a dismal activity so far to take the ambitious vision forward.
The challenges, from the fibre standpoint, however, continue to remain making the 5G ride not so smooth with fibre companies together with telecom carriers seeking the Narendra Modi-led government to accelerate efforts and carve out an incentive regime.
Reliance Jio, a pure-play 4G operator that has up its ante in fibre deployment for the ambitious fibre-to-the-home (FTTH) offering dubbed as JioGigaFiber said that that to incentivise telcos, the department should draw out incentives so that operators are not challenged to deliver on fiber which is a critical element for India’s digital growth.
Earlier, Mumbai-based Jio chief Mathew Oommen said that, “service providers should use incentives for creating a deeper fiber with the redundancy of routes,” and believes that incentives should be in the form of “conducive policy to attract more investments in building fibre infrastructure” by telcos.
“5G is an interesting initiative. There is still a lag in fiber deployments in remote locations. We have learnt how to roll out fiber throughout the country, and modern technologies aligned to 5G is also one of the important factors,” R&M chairman Hans Hess told ETT.
“5G needs fiber highways and tower fiberisation is essential to be accelerated and the establishment of National Fiber Authority similar to the National Highway Authority or NHAI. These aim towards a significant portion to be invested in fibre roll out,” Sterlite Technologies Limited (STL) Group CEO Anand Agarwal told ETT.
Company’s top executive said that the national policy has accorded fibre the status of a public utility, and since fibre is essential for both wireline and wireless networks, a greater level of confidence in fibre investment was much needed.
R&M’s Hess seconded Agarwal’s views, adding that a robust fibre-based backbone would be a vital element for a network of next generation of networks.
“There would be an increase in consumption of data due to the Internet of Things (IoT) proliferation. In order to produce more data faster, a strong backbone is needed that can be built on fiber,” the Swiss company’s executive added.
“5G technology will also require a multi-fold increase in small cells deployment, with each small cell having backhaul on fibre. We are woefully inadequate in terms of optic-fibre cable density both in urban and rural areas and a special focus for its densification in a time bound manner is essential for 5G deployments,” Agarwal added.
India’s fiber coverage in kilometre per capita works out to 0.09, which is far behind 0.87 for China and more than 1.3 for the United States and Japan, according to ICRA.
The Gurugram-based firm believes that fiber density in India would have to increase at least four-fold, and that would also mean that it would evolve as a separate industry in some time, similar to the telecom tower segment in the past two decades.
Active network sharing— Do it now
The 5G, based on low latency technology, requires a dense network to seamlessly deliver Internet connectivity enabled through a telecom infrastructure such as in-building solutions, small cells, fiber and fiberised mobile towers.
In a view to ease out financially-stressed operators, the government, in the policy has envisaged active network sharing that would allow telcos to share their networks and thereby reducing their capital (Capex) as well as operational (Opex) investment. Currently, the contours of the new regime are under a discussion stage together with the department and industry, and is expected to bring much respite to 5G rollouts.
The national policy, however, talks about encouraging sharing of active infrastructure by enhancing the scope of Infrastructure Providers (IP) and promoting deployment with incentives for common sharable, passive as well as active infrastructure.
“This (active network sharing) should be done in a more structured manner. All telecom service providers should make active sharing as freely as possible that could also help them reduce Capex as well as Opex in a scenario where margins are thin,” BSNL Chairman Anupam Shrivastava said.
Shrivastava further said that it would be going to help all service providers, and added that BSNL was offering its network for sharing and the same was expected from other operators.
Sector watchdog Telecom Regulatory Authority of India (Trai), in one of its whitepaper estimates the savings on account of active infrastructure sharing to the extent of 25-35% in Opex and 33-35% in Capex.
Network sharing, according to industry analysts, can significantly bring down 5G networks rollout as well as maintenance cost. New York-based McKinsey & Company in its finding has estimated the cost reduction of up to 40% — with major savings in rollout of small cells.
5G network, according to Taipa’s director general Dua, will enable a new set of applications such as the connected devices and cars which could become a reality only if the coverage becomes ubiquitous.
In order to have a pervasive 5G and for contiguous operations, there would have to be mushrooming of small cells over a city. Infrastructure providers can play a vital role in faster deployment of small cells that comes with a huge investment and thus support telcos to save on Capex and Opex,” he added.
Telecom carriers with 5G ambitions would be able to leverage 4G unified license (UL) coverage through dual connectivity or UL-sharing and would be able to cover larger areas with the same number of sites. 5G coverage compared to 4G coverage using 1800 MHz (megahertz) spectrum band would be about 60%.
A greenfield 5G operator, according to Taipa estimates, would need to deploy about 66% more sites to compensate for penetration losses.
Right-of-way— Not so right
The industry, demanding ease in Right-of-Way (RoW) rules, has been under continuous discussions with the regulator as well as policymakers for shaping up a comprehensive ‘dig-once’ common duct policy framework that according to the industry would help in the proliferation of 5G infrastructure across the country.
The next generation technologies are shaping the world economies and the smart cities would be built on a fibre-centric network for enabling ubiquitous and seamless connectivity. Trai is expected to come out with a policy enabling ‘common duct’ that would take telecom infrastructure to a next-level of growth.
In the last two years, post industry’s continuous rigorous follow-ups, only 13 states have to some extent aligned their policies with the Centre’s RoW rules notified in November 2016, according to Taipa.
“There is an urgent need for the states to align their telecom infrastructure policies with the Indian Telegraph Right of Way Rules to facilitate deployment of mobile infrastructure and connect the unconnected,” Dua added.
Deployment of small cells is significant for a proliferation 5G in India, the network rollout would have to be facilitated through enabling policies, which, according to the group, should include mandatory provisions for small cells at government lands and premises with new business models to excite municipal corporations and state governments.
The infrastructure providers such as Bharti Infratel, ATC Corporation and GTL Infrastructure demand a uniform RoW charges and single-window clearances nationwide to facilitate the telecom infrastructure for the digital delivery of services as envisaged by the Centre.