Anti-Suit and Anti-Anti-Suit Injunctions in Indian SEP Litigation – CrossBorder FRAND Disputes and the Delhi High Court’s New Jurisprudence

Standard essential patent litigation has always been an inherently global affair. A single smartphone implementing 4G or 5G cellular standards may infringe hundreds of patents held across dozens of jurisdictions and the manufacturer’s negotiations with a patent holder over a Fair, reasonable and non-discriminatory (FRAND) licence rarely confine themselves neatly to one country’s courts. What has changed in the past several years  and what now makes Indian SEP litigation a genuinely distinctive battlefield  is the emergence of an aggressive jurisdictional weapon: the anti-suit injunction, by which a court in one country orders a litigant to stop pursuing proceedings in another country altogether. When that weapon is met with a counter-injunction from the second court restraining enforcement of the first, India finds itself at the centre of a doctrinal escalation that traces its origins to private international law but now plays out with enormous commercial stakes in patent infringement disputes between global technology companies.

The Delhi High Court’s ruling in Interdigital Technology Corporation & Ors. v. Xiaomi Corporation & Ors., I.A. 8772/2020 in CS(COMM) 295/2020, decided on 3 May 2021, is the case that placed India squarely on the global map of this phenomenon. For the first time, an Indian court was called upon to decide not merely whether it could restrain a party from suing abroad  the conventional anti-suit injunction question that Indian courts had addressed since the Supreme Court’s foundational ruling in Modi Entertainment Network & Anr. v. W.S.G. Cricket Pte. Ltd., (2003) 1 SCR 480  but whether it could go a step further and restrain a party from enforcing an injunction that a foreign court had already granted against it. This is the anti-enforcement injunction, sometimes loosely grouped with the anti-anti-suit injunction (AASI) and the distinction between the two concepts, while subtle, is one that practitioners in this space must understand precisely.

This article traces the full architecture of anti-suit and anti-anti-suit injunction doctrine as it has developed in Indian SEP litigation: the general principles governing anti-suit injunctions under Indian law as laid down in Modi Entertainment, the specific factual background and reasoning of the InterDigital v. Xiaomi litigation, the conceptual distinctions between anti-suit, anti-enforcement and anti-anti-suit injunctions, the broader pattern of SEP litigation involving InterDigital, Xiaomi, OPPO and other handset manufacturers before the Delhi High Court and the comparative international backdrop  including the well-known English, German and Chinese cases that have shaped the global SEP anti-suit landscape  against which Indian doctrine must be understood.

The General Law of Anti-Suit Injunctions in India – Modi Entertainment

Before any SEP-specific analysis is possible, the foundational private international law principles governing anti-suit injunctions in India must be understood, because Indian courts in SEP cases have explicitly built upon this earlier framework rather than inventing an entirely new doctrine.

The Supreme Court’s ruling in Modi Entertainment Network & Anr. v. W.S.G. Cricket Pte. Ltd., 2003 AIR 1177, arose from a dispute concerning a non-exclusive English jurisdiction clause in a broadcast rights contract and required the Court to determine the circumstances in which an Indian court could restrain a party from pursuing proceedings in a foreign court. The Supreme Court laid down the now-settled three-part test: first, the defendant against whom the injunction is sought must be amenable to the personal jurisdiction of the Indian court; second, if the injunction is declined, the ends of justice will be defeated and injustice will be perpetuated; and third, the principle of comity  the mutual respect that one judicial system owes to another  must be borne firmly in mind. The Supreme Court added a further refinement applicable where more than one forum is available to the parties: the court should consider which forum is the more appropriate one (the forum conveniens) and may grant an anti-suit injunction in respect of proceedings that are oppressive or vexatious or that have been brought in a forum that is genuinely inconvenient for the parties (a forum non-conveniens).

The Modi Entertainment principles establish that an anti-suit injunction, although directed at a person rather than at a foreign court, nonetheless operates as an interference with that foreign court’s jurisdiction and Indian courts have consistently emphasised that the comity principle requires this power to be exercised only sparingly and with considerable caution. This caution is the backdrop against which every subsequent SEP anti-suit dispute in India must be assessed and it explains why Indian courts have approached the SEP cross-border injunction battles with detailed, case-specific reasoning rather than a generalised rule favouring either patentees or implementers.

The Conceptual Architecture  Anti-Suit, Anti-Enforcement and Anti-Anti-Suit Injunctions Distinguished

SEP litigation across multiple jurisdictions has generated a layered terminology that practitioners must use precisely, because the legal tests and the practical consequences differ across each category.

An anti-suit injunction (ASI) is an order by Court A restraining a party before it from instituting or continuing proceedings in Court B, a foreign court, typically on the ground that the proceedings in Court B are vexatious, oppressive or duplicative of issues already pending before Court A. This is the conventional remedy addressed in Modi Entertainment.

An anti-anti-suit injunction (AASI) is a step removed: it is an order by Court B restraining a party from enforcing an anti-suit injunction that Court A has already granted against it. In other words, where Court A has ordered a party not to sue in Court B and that party seeks to comply with Court A’s order by withdrawing or suspending its Court B proceedings, Court B can intervene and order the opposite  restraining the party from withdrawing or restraining the other litigant from enforcing the Court A injunction against it. The AASI is therefore a counter-strike against the first court’s attempt to control proceedings outside its own jurisdiction.

An anti-enforcement injunction (AEI) is closely related to but conceptually distinct from the AASI. Rather than directly countermanding the foreign anti-suit order before it takes effect, an anti-enforcement injunction restrains a party from enforcing or giving effect to an anti-suit injunction that has already been issued and which would otherwise compel withdrawal or suspension of the domestic proceedings. The practical effect of an AASI and an AEI can be very similar  both result in the domestic proceedings continuing despite the foreign court’s anti-suit order  but the AEI specifically targets the act of enforcement and compliance penalties (such as the daily fines that the Wuhan Court in the Xiaomi litigation had threatened), rather than restraining the foreign proceeding itself.

This terminology matters because the Delhi High Court, in the InterDigital v. Xiaomi judgment, was careful to characterise the relief it granted specifically as an anti-enforcement injunction rather than as a pure anti-anti-suit injunction, while commentary on the case has frequently  and not entirely incorrectly, given the practical overlap  described the order using both labels.

The Background to InterDigital v. Xiaomi – A Global FRAND Battle Reaches Delhi

The factual matrix of the InterDigital v. Xiaomi litigation is essential to understanding why the Delhi High Court reached the conclusions it did, because the timing and sequencing of events across two jurisdictions drove much of the court’s reasoning.

InterDigital Technology Corporation and its affiliated entities held several Indian patents relating to 3G and 4G cellular standard essential technology, including patents numbered 262910, 295912, 298719, 313036 and 320182. InterDigital instituted civil suits against Xiaomi Corporation and its affiliates before the Delhi High Court on 29 July 2020, registered as CS(COMM) 295/2020 and CS(COMM) 296/2020, alleging that Xiaomi’s 3G and 4G compliant cellular handsets infringed these Indian SEPs and seeking either a permanent injunction restraining infringement or, in the alternative, a direction that Xiaomi take a licence on FRAND terms. Summons in the suits were issued on 4 August 2020.

Critically, prior to InterDigital’s suit before the Delhi High Court, Xiaomi had already approached the Wuhan Intermediate People’s Court in China on 9 June 2020, seeking the determination of a global FRAND royalty rate for InterDigital’s entire SEP portfolio  a rate that, by virtue of being “global,” would necessarily encompass and effectively determine the royalty payable for the Indian patents as well, even though the Wuhan Court had no jurisdiction to adjudicate infringement of Indian patents as such. Then, after InterDigital filed its suit in Delhi, Xiaomi went a step further and applied to the Wuhan Court for an anti-suit injunction against InterDigital’s Delhi proceedings. On 23 September 2020, the Wuhan Court granted that anti-suit injunction, directing InterDigital to immediately withdraw or suspend its applications for temporary and permanent injunctions before the Delhi High Court concerning the SEPs at issue and threatening a substantial daily penalty  reported at approximately RMB 1 million (around US$154,000) per day  for non-compliance.

InterDigital, facing the prospect of being compelled by a Chinese court to abandon its Indian patent infringement proceedings or else incur a ruinous daily penalty, approached the Delhi High Court for interim relief restraining Xiaomi from enforcing the Wuhan anti-suit injunction. The Delhi High Court granted an ad-interim anti-enforcement injunction on 9 October 2020 and after detailed hearings, confirmed and made absolute that injunction in its final judgment dated 3 May 2021.

The Delhi High Court’s Reasoning in InterDigital v. Xiaomi

Justice C. Hari Shankar’s judgment is a careful and extensively reasoned engagement with both the general anti-suit injunction principles from Modi Entertainment and the specific question  described by the court itself as res integra, meaning a question not previously settled by Indian authority  of whether an Indian court could grant relief against the enforcement of a foreign anti-suit injunction.

The court’s central holding proceeded from a straightforward but powerful premise: patents are inherently territorial in nature. An Indian patent can only be infringed by acts occurring within India and only a court with jurisdiction over India  in this case, the Delhi High Court  can adjudicate whether such infringement has occurred and grant relief in respect of it. The Wuhan Court, however broad its asserted jurisdiction to determine “global” FRAND rates, had no jurisdiction whatsoever to determine infringement of InterDigital’s Indian patents, because Chinese courts cannot adjudicate the validity or infringement of patents granted under the law of another sovereign state. It followed that the Delhi High Court was the only forum competent to adjudicate InterDigital’s infringement claims concerning its Indian SEPs.

Given this, the court held that the Wuhan Court’s anti-suit injunction  insofar as it directed InterDigital to withdraw or suspend its Delhi proceedings concerning Indian patent infringement  was itself oppressive and vexatious in nature, because it sought to restrain a litigant from pursuing the only court in the world with jurisdiction over the cause of action in question. The court articulated the underlying principle as one of fundamental fairness: it is impermissible, as a general matter, for a court in one sovereign jurisdiction to injunct a party before it from pursuing its cause before a court in another jurisdiction, where that other jurisdiction is the sole competent forum for the claim. The Delhi High Court carved out only a narrow exception to this general rule  that such an injunction might be permissible in rare cases where the continuation of proceedings in the second jurisdiction is itself vexatious or oppressive towards the proceedings pending in the first court  and found, on the facts before it, that this narrow exception did not assist Xiaomi, because InterDigital’s Delhi suit, concerning Indian patent infringement, could not sensibly be characterised as vexatious or oppressive towards the Wuhan FRAND rate-setting proceedings.

The court was also influenced by the fact that InterDigital had no advance knowledge that Xiaomi had applied for the Wuhan anti-suit injunction until after the Wuhan Court had already issued its order  InterDigital had only been aware that Xiaomi had filed a complaint in Wuhan seeking determination of global FRAND rates, not that a specific application to restrain the Delhi proceedings was pending. This procedural circumstance reinforced the court’s view that allowing the Wuhan order to stand unchallenged would work a serious injustice on InterDigital, satisfying the second limb of the Modi Entertainment test.

On relief, the Delhi High Court granted InterDigital an anti-enforcement injunction restraining Xiaomi from enforcing or taking any steps to enforce the Wuhan Court’s anti-suit injunction against InterDigital, effectively allowing InterDigital’s Delhi patent infringement proceedings to continue notwithstanding the Wuhan order. In a particularly creative aspect of the relief, recognising that InterDigital might still face the daily penalty imposed by the Wuhan Court for its continued pursuit of the Delhi suit, Justice Hari Shankar directed Xiaomi to indemnify InterDigital against any such penalty  ordering that if the Wuhan Court imposed costs on InterDigital for pursuing the Delhi proceedings, Xiaomi would be required to deposit the equivalent amount with the Delhi High Court, from which InterDigital could then draw down. This indemnity mechanism neutralised the practical coercive effect of the Wuhan order without requiring the Delhi High Court to purport to directly overturn or nullify a foreign court’s order  a structurally elegant solution to a genuinely difficult comity problem, since the Delhi High Court had no power to set aside the Wuhan order as such, but could prevent its coercive financial consequences from being visited upon InterDigital for exercising its right to litigate in the only court with jurisdiction over its Indian patents.

The Doctrinal Significance  India’s First Anti-Enforcement and Anti-Anti-Suit Injunction

Commentary on the InterDigital v. Xiaomi ruling has consistently described it as India’s first anti-enforcement injunction and, in much of the trade press and legal commentary, as India’s first anti-anti-suit injunction, reflecting the practical overlap between these closely related forms of relief discussed above. The case’s significance lies less in inventing an entirely novel legal category  the underlying anti-suit injunction principles from Modi Entertainment remained the analytical foundation  and more in extending those principles to a genuinely new factual scenario: a foreign court’s attempt to restrain a litigant from pursuing patent infringement proceedings in the one jurisdiction where the underlying patent rights actually exist.

The court’s reasoning has been characterised by practitioners as following, while adapting to Indian conditions, a broader global trend in SEP anti-suit jurisprudence that has also played out before courts in Germany, the United Kingdom and the United States in parallel global litigation between SEP holders and handset manufacturers. The defendants in the Delhi proceedings had argued that the Wuhan Court’s FRAND rate-setting jurisdiction necessarily encompassed Indian rates as a component of any “global” rate and that allowing the Delhi proceedings to continue in parallel risked the two courts reaching inconsistent conclusions, thereby destroying the comity that courts owe to each other. The Delhi High Court was unmoved by this argument, holding that any overlap between the Wuhan FRAND rate-setting proceeding and the Delhi infringement proceeding was, at most, minor and that such overlap would only justify restraining the Indian proceedings if it rose to the level of making those proceedings genuinely oppressive or vexatious  a threshold the court found was not met.

The Broader InterDigital Litigation Ecosystem  Xiaomi, OPPO and the SEP Discovery Framework

The InterDigital v. Xiaomi anti-enforcement injunction did not arise in isolation; it sits within a wider and continuing pattern of SEP litigation before the Delhi High Court involving InterDigital and multiple Chinese handset manufacturers, which has generated an increasingly sophisticated body of Indian SEP procedural law extending well beyond the anti-suit and anti-enforcement injunction question itself.

InterDigital subsequently brought parallel proceedings against Guangdong OPPO Mobile Telecommunications Corporation, registered as CS(COMM) 692/2021 and CS(COMM) 707/2021, again concerning cellular technology and HEVC video compression SEPs, raising overlapping but distinct questions concerning the scope of pre-trial discovery in SEP disputes  specifically, whether and to what extent a defendant handset manufacturer can be compelled to disclose its existing licence agreements with other SEP holders as comparable evidence for determining FRAND rates. The Delhi High Court’s evolving jurisprudence in these cases, including its order of 31 May 2024 in the InterDigital v. OPPO matters, has drawn on and refined principles first articulated in the InterDigital v. Xiaomi confidentiality club rulings  themselves a separate but related strand of the same litigation in which the Delhi High Court addressed the structure of two-tier confidentiality clubs for the protection of sensitive licensing information exchanged during SEP discovery, a procedural innovation closely associated with Indian SEP practice generally and with the broader body of Indian FRAND case law that includes Koninklijke Philips N.V. v. Vivo Mobile Communication Co. Ltd. & Ors., CS(COMM) 383/2020.

This broader ecosystem of litigation illustrates an important point for practitioners: anti-suit and anti-enforcement injunction disputes in Indian SEP litigation rarely occur as standalone proceedings. They typically arise as one procedural battle within a much larger and more protracted infringement and FRAND-rate determination dispute that also encompasses confidentiality club structuring, discovery of comparable licences, claim construction and ultimately the substantive question of what royalty rate is fair, reasonable and non-discriminatory for the technology at issue.

Comparative International Context – The Global SEP Anti-Suit Landscape

The Indian InterDigital v. Xiaomi ruling did not emerge in a doctrinal vacuum; it reflects and responds to a broader pattern of cross-border anti-suit and anti-anti-suit injunction battles that has characterised global SEP litigation for the past several years, principally involving Chinese courts (most prominently Wuhan and Shenzhen), German courts (Munich and Mannheim, in particular), the England and Wales courts and US federal courts.

Chinese courts, beginning with the Wuhan Intermediate People’s Court’s anti-suit injunction in the Huawei v. Conversant dispute and continuing through the Xiaomi litigation against InterDigital and a parallel dispute involving Samsung and Ericsson, have developed a pattern of asserting jurisdiction to set global FRAND rates and then issuing anti-suit injunctions against SEP holders who pursue parallel infringement proceedings in other jurisdictions, often coupled with substantial daily non-compliance penalties of the kind imposed against InterDigital. German courts, by contrast, have shown a willingness to issue anti-anti-suit injunctions of their own  orders restraining a party from seeking or enforcing a foreign (typically Chinese) anti-suit injunction against German patent infringement proceedings  most notably in disputes before the Munich Regional Court. The English courts addressed a structurally similar problem in Unwired Planet International Ltd v. Huawei Technologies Co Ltd, [2020] UKSC 37, in which the UK Supreme Court upheld the jurisdiction of English courts to determine global FRAND terms and to grant an injunction against a SEP implementer who refused to accept a court-determined FRAND licence, establishing the English “FRAND injunction” framework that has itself become a touchstone for SEP holders seeking leverage against implementers who resist licensing on court-determined terms.

The Delhi High Court’s approach in InterDigital v. Xiaomi can be situated within this global picture as broadly aligned with the German and English judicial posture  protective of the SEP holder’s right to pursue territorial patent infringement remedies in the jurisdiction where the patent exists and resistant to other courts’ attempts to use global FRAND rate-setting jurisdiction as a vehicle for suppressing those territorial proceedings. India’s particular contribution to this global doctrinal conversation lies in the indemnity mechanism the Delhi High Court fashioned  using its equitable injunction powers not to purport to directly nullify the foreign court’s order, an approach that would raise its own comity concerns, but to neutralise its coercive financial sting through a creative indemnity arrangement that respects the formal existence of the foreign order while denying it practical effect against the Indian litigant.

Practical Implications for SEP Holders and Implementers Litigating in India

For SEP holders considering or already engaged in Indian patent infringement litigation, the InterDigital v. Xiaomi ruling provides important reassurance that Indian courts will protect the territorial integrity of Indian patent rights against foreign anti-suit injunctions that purport to compel withdrawal of Indian proceedings, particularly where the foreign court’s own jurisdiction does not and cannot extend to adjudicating Indian patent infringement as such. SEP holders should, however, be attentive to the procedural sequencing that proved important in the Xiaomi case  filing the Indian infringement suit promptly and seeking confirmation of jurisdiction and interim relief before a competing foreign anti-suit injunction can be obtained, strengthens the eventual case for anti-enforcement relief if a foreign anti-suit injunction subsequently issues. Where a foreign anti-suit injunction does materialise, prompt application to the Delhi High Court for interim anti-enforcement relief, supported by clear evidence of the territorial nature of the Indian patents at issue and the absence of jurisdiction in the foreign court to adjudicate infringement of those patents, mirrors the successful template established in the InterDigital litigation.

For handset manufacturers and other SEP implementers facing Indian infringement proceedings, the ruling signals that seeking a foreign anti-suit injunction to suppress Indian patent litigation is unlikely to succeed in shielding the implementer from continued Indian proceedings and indeed risks generating exposure to an Indian anti-enforcement or anti-anti-suit injunction with associated indemnity obligations, as occurred in the Xiaomi case. Implementers are better served, on the current state of Indian doctrine, by engaging substantively with the FRAND licensing question within the Indian proceedings themselves  including through the comparable licence discovery mechanisms developed in the Philips v. Vivo and subsequent OPPO litigation  rather than attempting to displace Indian jurisdiction through a foreign forum’s global rate-setting proceeding.

Conclusion

The InterDigital v. Xiaomi litigation represents a genuinely significant moment in Indian private international law and patent jurisprudence, extending the Modi Entertainment anti-suit injunction framework into the specifically global and high-stakes terrain of standard essential patent and FRAND licensing disputes. The Delhi High Court’s careful, territorially grounded reasoning  emphasising that Indian patents can only be adjudicated by Indian courts and that a foreign court’s broader FRAND rate-setting jurisdiction cannot be permitted to suppress that exclusive territorial competence  provides Indian SEP litigation with a clear and principled doctrinal foundation that other courts in the global SEP anti-suit landscape have, in their own ways, also reached.

The trajectory of this area of Indian law points toward continued sophistication as more SEP holders and implementers litigate before the Delhi High Court, which has emerged as India’s principal forum for standard essential patent disputes and has developed, through the InterDigital v. Xiaomi and InterDigital v. OPPO litigation in particular, an increasingly comprehensive procedural toolkit spanning anti-enforcement injunctions, confidentiality club structuring and comparable licence discovery. For practitioners advising global technology companies on cross-border SEP litigation strategy, India’s emergence as a jurisdiction willing to protect its own patent adjudicatory authority against foreign anti-suit pressure  while doing so through a careful, comity-respecting analytical framework rather than a blunt assertion of judicial supremacy  marks India’s arrival as a serious and sophisticated participant in the global architecture of SEP and FRAND dispute resolution.

References

1. Patents Act, 1970 (as amended)  https://ipindia.gov.in/writereaddata/Portal/IPOAct/1_31_1_patent-act-1970-11march2015.pdf
2. Code of Civil Procedure, 1908  Order XXXIX, Section 151  https://legislative.gov.in/sites/default/files/A1908-05.pdf
3. Modi Entertainment Network & Anr. v. W.S.G. Cricket Pte. Ltd., 2003 AIR 1177  https://indiankanoon.org/doc/1857811/
4. InterDigital Technology Corporation & Ors. v. Xiaomi Corporation & Ors., I.A. 8772/2020 in CS(COMM) 295/2020, Delhi High Court  https://indiankanoon.org/doc/159852349/
5. WIPO Lex  InterDigital Technology Corporation and Ors v Xiaomi Corporation and Ors (Case Summary)  https://www.wipo.int/wipolex/en/judgments/details/2166
6. Koninklijke Philips N.V. v. Vivo Mobile Communication Co. Ltd. & Ors., CS(COMM) 383/2020, Delhi High Court  https://delhihighcourt.nic.in
7. Unwired Planet International Ltd v. Huawei Technologies Co Ltd, [2020] UKSC 37  https://www.supremecourt.uk/cases/uksc-2018-0214.html
8. WTO TRIPS Agreement, Article 27–28 (Patent Rights)  https://www.wto.org/english/docs_e/legal_e/27-trips_04d_e.htm
9. Delhi High Court (Original Side) Rules, 2018  https://delhihighcourt.nic.in
10. WIPO  Standard Essential Patents and FRAND Licensing Resources  https://www.wipo.int/sme/en/ip_business/licensing/standards.htm
11. DPIIT  National IPR Policy, 2016  https://dpiit.gov.in/sites/default/files/National_IPR_Policy_English.pdf
12. CGPDTM  Official Patent Office Portal  https://ipindia.gov.in

Frequently Asked Questions:

1. What is an anti-suit injunction in the context of patent litigation?
   An anti-suit injunction is a court order restraining a party from initiating or continuing proceedings in a foreign court, typically issued when those foreign proceedings are considered vexatious, oppressive, or duplicative of a case already pending domestically.
2. What did the Delhi High Court decide in InterDigital v. Xiaomi?
   The Delhi High Court restrained Xiaomi from enforcing a Wuhan Court anti-suit injunction against InterDigital, allowing InterDigital’s Indian patent infringement proceedings to continue and ordering Xiaomi to indemnify InterDigital against any penalties imposed by the Chinese court.
3. What is the difference between an anti-suit injunction and an anti-anti-suit injunction?
   An anti-suit injunction stops a party from suing in a foreign court, while an anti-anti-suit injunction is a counter-order from the second court preventing a party from complying with or enforcing that foreign anti-suit injunction.
4. What are the Modi Entertainment principles for anti-suit injunctions in India?
   Laid down by the Supreme Court in Modi Entertainment Network v. WSG Cricket, the three-part test requires personal jurisdiction over the defendant, a risk of injustice if relief is denied, and due regard to international comity.
5. Why are SEPs and FRAND disputes prone to cross-border injunction battles?
   Because standard essential patents are held across multiple jurisdictions and a single device may implicate hundreds of patents, FRAND licensing negotiations and litigation frequently span several countries, creating jurisdictional conflicts between courts.

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