Testing the evolved packet core to prepare for LTE/4G billing

Essential Measurements to Assessing the Quality and Performance of the EPC Measurements must be rich, flexible, visual, complete, and represent an accurate real-time view of the network or device being tested. In order to get the insight they will need to optimize performance and accuracy, service providers must remember a few key areas in their test and validation methodology:

• Quality of Service (QoS). The quality of service, expressed in jitter, latency, packets dropped, and other measurements, is a key performance indicator in an all-IP network. QoS testing measures the degradation of a guaranteed bit rate flow, such as a voice call, when a sudden data surge occurs. QoS imbalances should be measured on a per service data flow, per-subscriber, and node level basis using triple-play and video-rich traffic.
• Quality of Experience (QoE). QoE tests validate the perceived quality of a voice or video stream.  Based on well-established standards, QoE tests are essential to assess the overall quality of the network from the user’s view, and they are especially effective as end-to-end measurements conducted between mobile equipment and the edge of the IP core network.
• Deep Packet Inspection (DPI). DPI is a cornerstone capability of the PDN-GW, since QoS enforcement is performed by inspecting and regulating ingress and egress traffic. Using DPI to simulate PDN behavior and to observe and report traffic violations, the EPC can certify service level agreements (SLAs). Triple-play and video-rich traffic is essential for testing node functions that enforce QoS, such as DPI.
• Subscriber behavior. Subscriber modeling emulates the mix, volume, and variability of mobile user communities. It is only by using rich traffic profiles, including video, file transfer, instant messaging, email, torrents, etc., that the EPC core network can be fully battle-tested.
• Charging. LTE charging occurs mostly in the PDN-GW and SGW. Interfaces have been defined for offline and online charging. A crucial EPC charging test involves checks and balances between the generated traffic trigger events and the measured charging events.

Simulating massive-scale, real-world mobile user behavior can successfully validate the EPC billing system. Stepping through a sequence of events that trigger charging data records (CDR), including establishment of dedicated bearers for VoLTE services or a conversational video session, roaming, access to a specific external network (APN), and many other events, operators can meet their billing needs. In fact, there are dozens of events that a particular operator may choose to monetize, each of which can trigger CDRs to be generated by the S-GW or P-GW and sent on to the OCS or OFCS.  By comparing the emulated event counts to the records in the OCF/OFCS, the accuracy of the charging system can be determined.
Preparing for LTE Billing – It’s All About Testing LTE wireless network deployment and the required interoperability with legacy technologies create new levels of network complexity. Fortunately, service providers will be able to capitalize on the promises of LTE through a full EPC evaluation using test tools for all mobile network elements from layer 2-7. The ability to create a realistic billing model through deciphering an average text message user versus the avid YouTube video watcher will allow service providers to charge according to usage. Providing service providers with deep, actionable-insight into their networks will allow them maximize new LTE infrastructures and provide proper billing structures to adhere to a high level of customer satisfaction.

Source: http://www.edn.com/design/test-and-measurement/4408352/2/Testing-the-evolved-packet-core-to-prepare-for-LTE-4G-billing–

LTE AND BEYOND

LTE, 4G, MME, PGW, SGW, Interfaces and beyond – How MME is selected – MME Selection procedure

It’s beed a while from last time, but here we go. Many times I saw people accesing this site looking for MME seletcion, or how LTE pick MME/SGW/PGW nodes. Hope the below clarifies.
In each LTE network the Internet Domain Name System (DNS) is widely used to handle the Dynamic Peer selection of the PDN-GW, SGW, MME, SGSN and HSS within the network. We could use statistic assingments but, hey! belive me, DNS is much easier if handled properly.
In a few days I will try to cover the details of DNS config for points mentioned below – stay tunned.
EPS Nodes sends the DNS Query message to the Internal DNS (iDNS) for the selection of EPS nodes for the following uses cases.

1. As part of the UE Attach the eNB will query the iDNS Server using the TAI for the address of the MME it should provide to that UE.
2. During UE attach the MME query the iDNS Server to select the PDN-GW (Packet Data Network Gateway, PGW) where a requested (subscribed) PDN connectivity (APN) is located. Selection can be based on the information provided to the MME, when the UE attaches to the network.
3. Following the PGW selection, the MME query the DNS Server to select an available SGW to serve the UE using the TAC, which in most cases is based on network topology and the location of the UE within the network, so that the best SGW is selected.
4. SGSN will query the DNS Server to resolve the Old MME using LAC, and RAC (taken from Old GUTI received from UE) during LTE to 3G/2G Handover.
5. MME will query the DNS Server to resolve the Old SGSN using NRI, LAC, and RAC (taken from P-TMSI received from UE) during 3G/2G to LTE Handover.
6. During attach the MME is configured to support the HSS Peer Service and Interface Associations towards the Diameter proxy/edge agent. These are static configurations in the MME towards the Diameter Proxy and no DNS query is initiated by the MME to select the Diameter Proxy.

Today it will about two of them referring to MME Selection, and the list above will be copied few times more when covering the SGW, PGW, SGSN and HSS selection.

DNS Interface

DNS interface is not via a 3GPP standardised interface, the eNBs, MMEs, SGSN and Diameter Proxy are connected (IP connectivity) to DNS servers in the EPS. Typically within the EPC network the EPS nodes would access the DNS servers via the Gn interface or O&M interface.

MME Selection

• Ref. to point 1:

eNodeB selects an available MME to serve the UE, based typically on network topology and the location of the UE within the network, so that the best MME is selected, e.g. to reduce the probability that the MME is changed. As part of the UE Attach the eNB will query the DNS Server using the TAI for the address of the MME. Typically the DNS will have a pool of MMEs to select from in response to the query. The format of the TAI FQDN is constructed as follows: tac-lb<TAC-low-byte>.tac-hb<TAC-high- byte>.tac.epc.mnc<MNC>.mcc<MCC>.3gppnetwork.org The DNS may provide more than one MME address (candidate set) from which the eNB can select a MME.

• Ref. to point 2:

SGSN query the DNS Server to identify the Old MME during LTE to 3G/2G Handover. It uses the old GUTI received from UE. There are procedures where the old MME must be contacted by a Release-8 SGSN supporting only Gn/Gp. The primary use case is context transfer during Handover.  A UE moving from eUTRAN to pre-Release-8 UTRAN/GERAN the UE will provide a derived P-TMSI based on a GUTI. As a result the source MME looks like a pre-Release-8 SGSN to a pre-Release-8 target SGSN node.  For a Release 8 Gn/Gp-SGSN to find all Gn and Gp interfaces of an MME based on the old GUTI and it would use a “Service Parameter” of ” x-3gpp-mme:x-gn”, ” x-3gpp-mme:x-gp”. For pre-Release 8 compatibility operators would continue to provision A/AAAA records for the corresponding Gn/Gp interfaces regardless of whether the source SGSN is pre-Release-8 or not. Gn/Gp interfaces are provisioned redundantly for both “.gprs” and “.3gppnetwork.org” top level domains.
Source: from my own experience

Source: http://www.lteandbeyond.com/2013/03/how-mme-is-selected-mme-selection-procedure.html#more

Making sense of mobile commerce between NFC, GPS and bar codes

As smartphone adoption skyrockets, consumer behavior is shifting more toward mobile-based actions for everything. One of the latest hot topics when it comes to consumer behavior is how we have started to use our mobile phones for commerce and, more specifically, as a payment solution.

Google, Apple, Paypal and even traditional credit card companies such as MasterCard, have all developed their own mobile payment products, making significant strides toward changing how consumers pay for everyday goods.

However, no one has really cracked the code on what the best solution is for mobile payments.

Chips down We not only have to consider issues such as wireless carrier, retailer and consumer adoption, but we also need to determine which technology is best and safest.

Until we have a mobile payment solution that provides consumers with a sense of true security, reduces barriers to entry for each player in the larger mobile commerce ecosystem, and is easy for retailers and carriers to get behind, we will have to keep searching for a solution.

Let us take a look at the current landscape to try to make sense of mobile commerce today first by reviewing the technologies that power mobile commerce, and then exploring the current products we can use.

There are three main technologies that are used in mobile commerce: NFC, GPS and standard bar codes.

NFC, which stands for “near field communication,” uses radio waves to send payment information from one device to another. It is specifically designed to work over very small distances – only a few centimeters – to avoid the POS (point of sale) terminal from recognizing users for reasons other than a transaction.

While this is a benefit, it also means that the consumer is invisible until he or she is paying for something. Vendors have no way of knowing if a loyal customer, or any potential customer for that matter, has entered their store.

If merchants were aware of consumer presence earlier, they could send promotions or coupons directly to the consumer, increasing the likelihood of them making a purchase.

This is where GPS has a leg up – it uses location-aware functionalities found within our phones to establish a connection between a consumer and the store.

With this, vendors can alert consumers to special offers nearby and specific stores can be alerted when loyal customers walk in their doors.

Also, there is no additional equipment needed – location-based technology is found in all phones, whereas NFC is not.

Then there are bar codes, which are the most familiar to us.

Used by players such as Apple, a bar code will appear on your smartphone screen and customers simply scan their phone to make a payment.

If you head out to Starbucks for an afternoon coffee break, you will likely see a few customers paying this way.

The issue with NFC is adoption.

Leading up to the iPhone 5 launch in September, rumors flew that Apple planned to incorporate NFC into the new devices.

However, we now know that Apple made the decision to leave it out and stick with Passbook, an app that compiles all of our coupons, promotions, loyalty cards and more into one easily accessible place.

Apple isn’t the only one to leave NFC out of the mix – the leading mobile carriers, Sprint excluded, have joined together to create an NFC alternative called ISIS, and have forbidden the activation of NFC in any of the devices that operate on their networks.

Getting carded Recently, Google Wallet launched the “Google Wallet Card,” which was a big surprise to the industry as many originally thought that the key aspect of the digital wallet offering was its solution to the problem of carrying around a traditional wallet filled with cash and credit cards.

While it was a departure from the vision of a “cardless” future, it is also indicative of the larger issue.

The card is Google’s strategy to get around the carriers and embed the NFC technology into this card instead of relying on a smartphone.

Consumers are still able to have the same experience of checking point balances and perform other tasks on their phone, without Google needing access to the phone’s chip.

But if we are moving toward a digital wallet, is providing another physical card to carry around really a step in the right direction?

Looking at the options that are currently on the table, ISIS, the joint venture between AT&T, T-Mobile and Verizon, seems to be the most viable contender for long-term success.

It is a mobile app that allows users to store their credit card information and then simply tap their phone to the POS to make a payment via NFC.

This app not only stores your Amex, Visa or other credit card information, it can also store debit cards, reward cards, discount coupons, payment coupons, tickets and transit passes.

As the venture has broad carrier support, ISIS has a leg up on Google, which is offering a similar solution.

Dealing with it The platform, technology or product that is most likely to succeed is the one that is most easily adoptable by all parties involved in the ecosystem.

For those of you who just got a new smartphone, you are likely blown away by the ease of use and how highly intuitive it is to use it – even a four-year-old can figure it out.

The same must go for mobile payment solutions, but they also must incorporate the features that we are used to being able to access on our desktop computers: the deals and promotions, especially when they are becoming increasingly popular mobile marketing tactics.

But it is still early and we are still in the stage of warming up consumers to the idea that commerce can truly be mobile-based.

It will take some time for consumers to feel comfortable to leave the house with just their phone, knowing it can act like their wallet as well.

While Passbook has taken a great first step as it will help us get used to moving many of the non-transactional cards into the digital wallet, the long-term solution must have three components: phone integration and carrier support, point-of-sale integration and a compelling reason for consumers to make the switch.

ALTHOUGH MANY new providers are delivering solutions to the phone – and some even the POS terminal – the real question is, “Why will the consumer switch?” And it still remains murky.

What we need is an infrastructure that rewards consumers for using the transaction technology, and that automatically ties in loyalty cards and points data. While ISIS appears to have the best chance, only time will tell.

Source: http://www.luxurydaily.com/making-sense-of-mobile-commerce-between-nfc-gps-and-bar-codes/

“Small Cells are the hot topic of the mobile industry”

Next Generation Optical Networking Blog

We spoke to Kevin Baughan, Director of Metro Wireless at Virgin Media and speaker at the upcoming Transport Networks for Mobile Operators event, who gave his thoughts on the latest topics in the industry. What do you think of his comments?

What do you see as the biggest challenges facing operators in the transport network arena?

The explosive growth rate in mobile data. A growth trajectory that has only just kicked off, as our smartphones and tablets become an integral and increasingly critical component of our digital lives. As a fixed network operator we have already lived through an equivalent experience as dial up networks gave way first to broadband  and then to superfast broadband services. It is a challenge therefore that Virgin Media Business understands well and through our fibre based Small Cell Hosting Service, it is one that we know how to solve.

What are looking forward to…

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